docs: add talk-to-data case study

Add anonymized architecture, governance examples, diagrams, and interview materials.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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# Talk-to-Data: Semantic Analytics for Enterprise Quotations
**A POC case study in governance-first semantic layer design: SAP → Snowflake → Cortex → Chatbot.**
---
## Problem Statement
Sales and operations teams across multiple regions handle thousands of quote requests monthly. Each inquiry requires:
- **Manual research**: Discount policy lookups, product classification, customer contract data
- **Cross-system queries**: SAP for pricing, internal databases for agreements, email chains with ops
- **Coordination overhead**: Sales emails ops, ops researches and replies (5-30 minutes per quote)
- **Scale challenge**: 30+ salespersons generating inquiries daily across the sales organization
**Result**: Quote turnaround times of 5-30 minutes, even for routine requests. Ops team context-switches between email, SAP, and spreadsheets. Sales can't get answers fast enough to close deals.
---
## Solution: Semantic Analytics Layer + Cortex Guardrails
**Core insight**: Build a semantic layer that serves as the single source of truth for quote logic, then consume it via two interfaces: BI dashboards and an LLM-powered chatbot. Governance lives in the data layer, not in prompts.
### Architecture Overview
```
┌─────────────────────────────────────────────────────────────┐
│ SAP ERP (Sales, Pricing, Discounts) │
│ Updated daily via batch extract (05:00 UTC) │
└────────────────────────┬────────────────────────────────────┘
Daily ELT Job
┌────────────────────────▼────────────────────────────────────┐
│ Snowflake Raw Layer │
│ - raw.quotations (document, line item, amount, ...) │
│ - raw.discount_conditions (discount tiers, policies) │
│ - raw.customer_master (customer codes, agreements) │
└────────────────────────┬────────────────────────────────────┘
dbt Staging
┌────────────────────────▼────────────────────────────────────┐
│ Staging Layer (STAGING schema) │
│ - Column mapping, type casting, null handling │
│ - No business logic, just data preparation │
└────────────────────────┬────────────────────────────────────┘
dbt Transforms
┌────────────────────────▼────────────────────────────────────┐
│ Transform Layer (TRANSFORM schema) │
│ - Join discount conditions, policies, agreements │
│ - Calculate: discount tiers, totals, exceptions │
│ - Apply: governance flags, audit columns │
│ - Models: trf_quotation, trf_chatbot_quotation │
└────────────────────────┬────────────────────────────────────┘
Semantic Views (DDL)
┌────────────────────────▼────────────────────────────────────┐
│ Semantic Layer (DISTRIBUTE_DDL schema) │
│ - sv_quotation: Full BI consumption │
│ - sv_chatbot_quotation: LLM-optimized dimensions │
│ - Exposes: business logic (discounts, policies) │
│ - Hides: implementation details (temp tables, keys) │
└────────────────────────┬────────────────────────────────────┘
Cortex Analytics Guardrails
┌───────────────┴───────────────┐
│ │
┌────────▼──────────────┐ ┌─────────▼─────────────┐
│ Snowflake UI │ │ Internal Workspace │
│ (BI Dashboard) │ │ (Chatbot + LLM) │
│ │ │ │
│ - Visual analysis │ │ - Quote Q&A │
│ - Sales reporting │ │ - Prompt engineering │
│ - Ops monitoring │ │ - Real-time answers │
└───────────┬──────────┘ └──────────┬────────────┘
│ │
│ <1 minute turnaround
End Users (Sales, Ops)
```
---
## Stack: Why Each Layer?
### SAP → Snowflake ELT (Daily Batch)
- **Why**: Quotation data lives in SAP; Snowflake is the reporting warehouse
- **How**: Daily batch extract (05:00 UTC), once-per-day refresh sufficient for quote workflow (real-time inventory not required)
- **Trade-off**: Once-daily freshness OK for most quote requests; could escalate to hourly for real-time dashboard if needed
### Staging → Transform → Semantic Layer (dbt)
- **Why dbt?**
- **Lineage**: Column-level traceability (SAP field → transform → semantic dimension)
- **Testability**: Unit tests on discount calculations, data quality checks
- **Team reuse**: SQL-first approach, skill portability across data team
- **Governance**: Schema.yml documents business logic and access rules
- **Reproducibility**: Version-controlled transformations, audit trail of changes
- **Why separate layers?**
- **Staging**: Decouples source-system brittleness from business logic
- **Transform**: Concentrates business rules (discount math, policy flags) in one place
- **Semantic**: Exposes curated dimensions to downstream consumers; hides technical debt
### Snowflake Semantic Views
- **What**: Semantic views (DDL) wrap transform models; define dimensions, facts, and synonyms
- **Why**:
- Define the contract between data and consumers (Sales, Cortex)
- Synonyms enable natural-language queries ("desconto cliente" → `discount_customer_pct`)
- Consistent schema across BI dashboards and LLM consumption
- **Example**: A chatbot user asks "What's the customer discount on this quote?" The semantic layer maps "customer discount" (natural language) to `discount_customer_pct` (column), and Cortex applies guardrails (hides the raw percentage and shows only "within policy" or "requires approval")
### Cortex Analytics + Guardrails
- **What**: Snowflake's native LLM platform + custom governance policies
- **Why Cortex, not custom LLM?**
- Built-in guardrails: protection of sensitive information, access control, and cost controls
- Fast prototyping: Cortex agents consume Snowflake semantic views directly (no ETL to another system)
- Governance-as-code: Policies live alongside data, versioned, audited
- Security: Data stays in Snowflake; LLM calls don't leak sensitive data
- **Trade-off**: Cortex is Snowflake-specific (vs. generic LLM + Anthropic); acceptable for POC, revisit if multi-cloud needed later
### Dual Consumption (Snowflake UI + Internal Workspace)
- **Snowflake UI**: Native BI dashboards for sales/ops teams. Semantic model feeds Power BI or Tableau directly.
- **Internal Workspace**: Existing chatbot environment. Cortex queries the semantic layer + prompt engineering layer refines responses.
- **Why two interfaces?** Users consume data differently — dashboards for exploration, chatbot for direct answers. Semantic layer unified the source, reducing maintenance.
---
## Key Decisions & Trade-offs
| Decision | Rationale | Trade-off |
|----------|-----------|----------|
| **Governance-first** | Discount policies, protection of personal and customer information, and exception escalation built into the data layer | Requires upfront effort to define policies; can't skip it for "speed" |
| **Semantic views (DDL)** | Single contract between data → BI/LLM | Requires mapping business terms to columns; initial work to get synonyms right |
| **Once-daily batch** | Sufficient for quote workflow; reduces ELT complexity | Not real-time; acceptable for POC; upgrade to hourly if pilot shows need |
| **Cortex (vs. custom LLM)** | Fast prototyping, built-in guardrails, stays in Snowflake ecosystem | Cortex-only (could integrate with Anthropic later) |
| **Separate transform model per interface** | `trf_quotation` for BI, `trf_chatbot_quotation` for LLM — optimize each | Slight duplication; worth it if interfaces have different freshness/cardinality needs |
---
## Governance: How We Built Safety In
Governance is not a checklist; it's embedded in the data layer.
### 1. **Discount Policy Guardrails**
- **Rule**: No discount exceeds the configured policy ceiling
- **Implementation**:
- Transform model calculates `discount_above_ceiling` flag
- Cortex policy hides raw discount percentages; shows only "Within Policy" or "Requires Approval"
- Chatbot escalates flagged quotes to ops team (max 10 escalations/hour to prevent bot spam)
- **Effect**: Sales can't accidentally propose an unapproved discount; exceptions are visible and auditable
### 2. **Protection of Personal and Customer Information**
- **Rule**: The chatbot must not expose customer names, contact details, or negotiated terms unless the user is authorized
- **Implementation**:
- `sv_chatbot_quotation` includes only aggregated customer data (customer_id, portfolio_code)
- Cortex policy replaces `customer_name` with "[Customer information protected]" in chatbot responses
- Exception: Sales team in authorized role can see unmasked values via dashboard
- **Effect**: Chatbot can answer quote questions without leaking customer contracts
### 3. **Access Control & Audit Trail**
- **Rule**: Different roles see different data
- Sales: Can query `sv_chatbot_quotation` (limited fields, no raw discounts)
- Ops: Can query `sv_quotation` (full discount details, for policy review)
- Cortex Agent: Can query `sv_chatbot_quotation` only (locked down for LLM)
- **Implementation**: Snowflake role-based access control (RBAC) + Cortex `authorized_teams` config
- **Audit**: All queries logged; policy violations trigger alerts
### 4. **Data Freshness Contract**
- **Rule**: Chatbot rejects queries on stale data; warns user if data is > 24 hours old
- **Implementation**:
- dbt model adds `load_timestamp` column
- Cortex quality gate checks: `current_timestamp() - load_timestamp < 24 hours`
- Failure: Returns "Data unavailable; please retry in 1 hour" (prevents stale-data surprises)
---
## Results: From POC to Impact
### Estimated Impact (Based on User Interviews)
- **Quote turnaround**: 5-30 min (email + manual lookup) → <1 min (chatbot query)
- Savings per quote: 5-30 minutes
- Pilots with 5 sales reps: ~50+ hours/week freed (estimated)
- Extrapolation: 30+ sales team × 5 hours/week = 150+ hours recovered org-wide
- **Error reduction**: Discount exceptions caught by policy guardrails (vs. manually reviewed)
- **Team velocity**: POC shipped in weeks (not months), governance patterns established for scale
### Why This Matters for Delivery Managers
1. **Governance-first approach**: We didn't build a prototype and hope for policy later. Guardrails were baked in from day one.
2. **Reusable patterns**: The semantic layer + Cortex + dbt playbook works for any quote/contract/discount domain. Next use cases ship faster.
3. **Measurable before scale**: We validated impact with a small pilot; ready to scale to 30+ users with confidence.
4. **Ops visibility**: Sales/ops can see what the bot is doing (audit logs, escalation flags); not a black box.
---
## How to Use This Repo
### Deliverables
- **`dbt/`**: Anonymized dbt models (staging, transforms, semantic views)
- `models/staging/stg_*.sql` — Raw layer transformations
- `models/transform/trf_*.sql` — Business logic
- `models/distribute_ddl/sv_*.yml` — Semantic views with synonyms
- **`cortex/`**: Governance config (information protection, access control, audit rules)
- `cortex_governance_config.yaml` — Guardrails, freshness contracts, LLM policies
- **`docs/`**: Architecture diagrams, decision logs
- `architecture_dag.md` — Data flow Mermaid diagram
- `decisions.md` — Architecture decision records (ADRs)
- **`README.md`**: This file (the narrative for interviewers/stakeholders)
### How to Adapt This to Your Domain
1. **Replace discount logic** with your domain (e.g., pricing tiers, contract terms, approval workflows)
2. **Adjust freshness** (once-daily to hourly/real-time) based on your use case
3. **Modify semantic dimensions** to match your business terminology
4. **Update Cortex policies** for your personal-information and governance rules
5. **Test with a small pilot** (5-10 users) before org-wide rollout
---
## Lessons Learned
### What Worked
**Semantic views as the contract**: Defining dimensions + synonyms upfront saved rework later. Sales/ops understood the model; Cortex had clear field mappings.
**Governance in the data layer**: Embedding discount flags and information-protection rules in dbt/Cortex meant the bot couldn't bypass them. No workaround hacks possible.
**Once-daily batch sufficient**: For this workflow, 24-hour freshness was OK. We didn't need real-time complexity (yet).
**dbt for team alignment**: SQL-first + schema docs meant the data team and business stakeholders spoke the same language. Onboarding new people was fast.
### What We'd Change at Scale
⚠️ **Real-time discount updates**: If pilot shows sales need <1hr freshness on policy changes, escalate to hourly ELT.
⚠️ **Multi-region governance**: Current config is single-region (BR). If expanding to US/CA, add region-specific discount tiers and approval workflows.
⚠️ **Cortex cost**: Monitor Cortex token usage as chatbot volume scales. Current config has cost controls (monthly budget, per-query max tokens); may need aggressive pruning at scale.
⚠️ **Semantic view complexity**: If adding more dimensions (15→50), consider splitting into focused semantic views (e.g., `sv_quote_discounts`, `sv_quote_compliance`) to keep queries fast.
---
## Tech Stack Summary
| Component | Tool | Why |
|-----------|------|-----|
| **Data Warehouse** | Snowflake | Scalable, built-in Cortex, governance features |
| **Transformations** | dbt + Jinja | SQL lineage, testability, team skill reuse |
| **Semantic Layer** | Snowflake DDL | Data contract, synonyms for NLP, single source of truth |
| **AI/Guardrails** | Cortex Analytics | Native LLM, information protection, access control, cost controls |
| **Consumption 1** | Snowflake Native App / BI Tool | Dashboard for ops/sales exploration |
| **Consumption 2** | Internal Workspace + Prompt Engineering | Chatbot for direct question-answering |
| **Infrastructure** | Cloud-native Snowflake | No ops overhead, pay-per-query |
---
## FAQ
**Q: Can I use this with a different warehouse (e.g., BigQuery, Redshift)?**
A: Yes. Adapt the dbt dialect (BigQuery: `jinja-sql`, Redshift: `redshift` profile). Cortex is Snowflake-native; substitute with your own LLM guardrails (policy enforcement layer).
**Q: Is once-daily refresh really enough?**
A: For quote research, yes. If you need real-time pricing updates, escalate to hourly ELT. The architecture supports it; just change the schedule in your orchestrator.
**Q: How do I handle discount exceptions?**
A: Cortex policy flags them and escalates to a human review queue (max 10/hour). Ops team approves or rejects in Snowflake; bot learns the decision for future similar quotes.
**Q: What if I need to scale to 500+ users?**
A: Semantic layer architecture scales horizontally. Snowflake handles concurrency. Monitor Cortex token usage and partition semantic views if queries slow down. dbt stays the same.
**Q: Can I export this as a Snowflake Native App for partners?**
A: Yes. Package the semantic views + Cortex policies as an app; partners can install it and use the chatbot without seeing raw data.
---
## Next Steps
1. **Expand pilot**: Rollout to 30+ sales team over 4 weeks
2. **Measure impact**: Track quote turnaround times, bot usage, escalation rates
3. **Iterate on policies**: Refine discount rules and information-protection controls based on pilot feedback
4. **Add new domains**: Reuse the semantic layer pattern for contracts, serviceability, pricing
5. **Scale LLM**: Move from proof-of-concept to production volume (monitor cost, latency)
---
## Contact & Questions
This case study demonstrates:
- Governance-first architecture for enterprise AI
- Semantic layer design (SAP → dbt → Snowflake → LLM)
- Operationalizing guardrails and audit trails
- Shipping production-ready POCs in weeks
For questions about the design decisions, data flow, or how to adapt this to your domain, reach out.
---
**Co-authored by Copilot**

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# Quotation Semantic Layer - Data Flow DAG
# SAP Source -> Snowflake -> dbt Transforms -> Semantic Views -> Cortex -> Chatbot Output
graph LR
SAP["🗄️ SAP ERP System<br/>(Sales & Discount Data)"]
EXT["📥 Snowflake<br/>External Stage"]
RAW["raw.quotations<br/>raw.discount_conditions"]
STG["STAGING Layer<br/>stg_quotes<br/>stg_discount_conditions<br/>stg_product_master"]
TRF["TRANSFORM Layer<br/>trf_quotation<br/>trf_chatbot_quotation"]
DIM["Reference Dimensions<br/>dim_customer_discount_policy<br/>dim_product_portfolio<br/>fct_agreement_discounts"]
SEMA["SEMANTIC LAYER<br/>sv_quotation<br/>sv_chatbot_quotation"]
CORTEX["Cortex Analytics<br/>Guardrails & Information Protection<br/>Access Control<br/>Freshness Contract"]
UI["Snowflake UI<br/>(BI Dashboard)"]
CHAT["🤖 Internal Workspace<br/>(Chatbot)"]
SAP -->|Daily Batch 05:00 UTC| EXT
EXT -->|Load| RAW
RAW -->|Column mapping<br/>Type casting| STG
STG -->|Join dimensions<br/>Calculate discounts<br/>Apply governance flags| TRF
DIM -->|Enrich with policies| TRF
TRF -->|Expose semantic<br/>business logic<br/>Hide implementation| SEMA
SEMA -->|Apply guardrails<br/>Protect sensitive information<br/>Enforce freshness| CORTEX
CORTEX -->|Query & Visualize| UI
CORTEX -->|LLM consumption<br/>Prompt engineering layer| CHAT
CHAT -->|<1 min<br/>Quote Answers| USER["👤 Sales & Ops<br/>Team"]
UI -->|Dashboard<br/>Reporting| OPS["📊 Operations<br/>Team"]
SEMA -.->|Data Contract<br/>Lineage| AUDIT["🔒 Audit & Compliance<br/>- Access logs<br/>- Policy changes<br/>- Exception escalations"]
style SAP fill:#d4a574
style CORTEX fill:#ff9999
style SEMA fill:#99ccff
style CHAT fill:#99ff99
style USER fill:#ffcc99
style AUDIT fill:#cc99ff
classDef layer_raw fill:#e1e4e8
classDef layer_stg fill:#d0d7de
classDef layer_trf fill:#adb8c1
classDef layer_sema fill:#6e7681
class RAW layer_raw
class STG layer_stg
class TRF layer_trf
class SEMA layer_sema

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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Talk-to-Data: Architecture Animated Diagram</title>
<script src="https://cdn.jsdelivr.net/npm/mermaid@10/dist/mermaid.min.js"></script>
<style>
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
margin: 0;
padding: 20px;
background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
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border-radius: 6px;
border-left: 4px solid #3498db;
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display: flex;
justify-content: center;
min-width: 760px;
}
.mermaid svg {
width: 100%;
max-width: 920px;
height: auto;
overflow: hidden;
}
.mermaid .nodeLabel,
.mermaid .edgeLabel {
font-size: 16px !important;
}
.mermaid .edgeLabel {
background: transparent !important;
padding: 2px 4px;
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.mermaid .edgeLabel:has(span:empty) {
display: none;
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.legend {
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grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
gap: 15px;
margin-top: 30px;
padding-top: 20px;
border-top: 1px solid #ecf0f1;
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display: flex;
align-items: center;
font-size: 13px;
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background: #ecf0f1;
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.section h2 {
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font-size: 18px;
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color: #555;
line-height: 1.6;
margin: 10px 0;
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.flow-step {
display: flex;
align-items: center;
margin: 15px 0;
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background: white;
border-radius: 4px;
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.flow-step span {
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min-width: 110px;
flex-shrink: 0;
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flex: 1;
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code {
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@keyframes flow {
0% { opacity: 0.3; }
50% { opacity: 1; }
100% { opacity: 0.3; }
}
.animate-flow {
animation: flow 2s ease-in-out infinite;
}
</style>
</head>
<body>
<div class="container">
<h1>Talk-to-Data: Semantic Analytics Architecture</h1>
<p class="subtitle">SAP → Snowflake → dbt → Cortex → Chatbot | <1 minute quote answers</p>
<div class="diagram-wrapper">
<div class="mermaid">
graph TD
SAP["SAP ERP<br/>Quotes and discounts<br/>Daily batch"]
RAW["Snowflake raw data"]
STG["dbt staging<br/>Clean and standardize"]
TRF["dbt transforms<br/>Business rules and flags"]
SEMA["Semantic views<br/>Business terms and lineage"]
CORTEX["Cortex Analytics<br/>Guardrails and audit"]
UI["Snowflake UI<br/>Dashboards"]
CHAT["Internal workspace<br/>Chatbot"]
USER["Sales and operations<br/>30+ users<br/><1 min estimated answer"]
AUDIT["Audit trail<br/>Access and exceptions"]
SAP --> RAW
RAW --> STG
STG --> TRF
TRF --> SEMA
SEMA --> CORTEX
CORTEX --> UI
CORTEX --> CHAT
UI --> USER
CHAT --> USER
SEMA -.-> AUDIT
style SAP fill:#d4a574,stroke:#333,stroke-width:2px,color:#fff
style CORTEX fill:#ff9999,stroke:#c0392b,stroke-width:2px,color:#fff
style SEMA fill:#99ccff,stroke:#2980b9,stroke-width:2px,color:#fff
style CHAT fill:#99ff99,stroke:#27ae60,stroke-width:2px,color:#000
style USER fill:#ffcc99,stroke:#e67e22,stroke-width:2px,color:#000
style AUDIT fill:#cc99ff,stroke:#8e44ad,stroke-width:2px,color:#fff
style RAW fill:#e1e4e8,stroke:#666,stroke-width:1px
style STG fill:#d0d7de,stroke:#666,stroke-width:1px
style TRF fill:#adb8c1,stroke:#666,stroke-width:1px
style RAW fill:#e1e4e8,stroke:#666,stroke-width:1px
</div>
</div>
<div class="legend">
<div class="legend-item">
<div class="legend-color" style="background: #d4a574;"></div>
<span><strong>SAP Source:</strong> Daily batch extract</span>
</div>
<div class="legend-item">
<div class="legend-color" style="background: #e1e4e8;"></div>
<span><strong>Raw:</strong> Unmodified data</span>
</div>
<div class="legend-item">
<div class="legend-color" style="background: #d0d7de;"></div>
<span><strong>Staging:</strong> Data preparation</span>
</div>
<div class="legend-item">
<div class="legend-color" style="background: #adb8c1;"></div>
<span><strong>Transform:</strong> Business logic</span>
</div>
<div class="legend-item">
<div class="legend-color" style="background: #99ccff;"></div>
<span><strong>Semantic:</strong> Data contract</span>
</div>
<div class="legend-item">
<div class="legend-color" style="background: #ff9999;"></div>
<span><strong>Cortex:</strong> AI guardrails</span>
</div>
<div class="legend-item">
<div class="legend-color" style="background: #99ff99;"></div>
<span><strong>Chatbot:</strong> User interface</span>
</div>
<div class="legend-item">
<div class="legend-color" style="background: #cc99ff;"></div>
<span><strong>Audit:</strong> Compliance trail</span>
</div>
</div>
<div class="section">
<h2>Data Flow Stages</h2>
<div class="flow-step">
<span>1. Source</span>
<p>SAP ERP systems extract quotation, discount, and customer data daily at 05:00 UTC. Data includes quotation identifiers, line items, pricing, and discount conditions.</p>
</div>
<div class="flow-step">
<span>2. Raw</span>
<p>Snowflake External Stage ingests CSV/Parquet. Raw schema preserves source structure without modification. Data quality checks validate row counts, null patterns.</p>
</div>
<div class="flow-step">
<span>3. Staging</span>
<p><code>stg_*</code> models rename columns, cast data types, and handle nulls. Example: source quotation ID → <code>quote_id</code>, source amount → <code>net_value</code>. No business logic yet.</p>
</div>
<div class="flow-step">
<span>4. Transform</span>
<p><code>trf_quotation</code> joins customer policies, product portfolios, and agreement discounts. Calculates discount totals, applies governance flags (e.g., <code>discount_above_ceiling</code>). Two models: <code>trf_quotation</code> (BI) and <code>trf_chatbot_quotation</code> (LLM-optimized).</p>
</div>
<div class="flow-step">
<span>5. Semantic</span>
<p>Snowflake DDL semantic views expose curated dimensions and facts. Includes synonyms for natural language (e.g., "desconto cliente" → <code>discount_customer_pct</code>). Single source of truth for BI dashboards and LLM queries.</p>
</div>
<div class="flow-step">
<span>6. Cortex</span>
<p><a href="https://docs.snowflake.com/en/user-guide/snowflake-cortex/cortex-analyst" target="_blank" rel="noopener noreferrer">Cortex Analyst</a> applies guardrails: hides raw discount percentages, protects customer names, checks data freshness, enforces role-based access, and logs all access. LLM queries go through here.</p>
</div>
<div class="flow-step">
<span>7. Consume</span>
<p><strong>Snowflake UI:</strong> Dashboards for ops/sales teams (full data visibility). <strong>Internal Workspace:</strong> Chatbot interface (guardrail-filtered data). Both consume the same semantic layer; governance rules ensure consistency.</p>
</div>
</div>
<div class="section">
<h2>Why This Architecture?</h2>
<p><strong>Governance-first:</strong> Guardrails (discount policies, protection of personal and customer information, and audit logs) are embedded in the data layer, not bolted on to the LLM prompt. The bot can't bypass policy; it's enforced by Cortex + dbt.</p>
<p><strong>Semantic contract:</strong> The semantic layer (sv_quotation, sv_chatbot_quotation) defines the agreement between data engineers, BI teams, and LLM consumers. Column definitions, synonyms, and access rules are version-controlled.</p>
<p><strong>Team efficiency:</strong> dbt lineage shows how every dimension flows from SAP → semantic layer. Data engineers and business analysts can trace a discount calculation back to SAP in seconds. Onboarding takes days, not weeks.</p>
<p><strong>Prototyping speed:</strong> Snowflake + Cortex means we didn't build custom infrastructure. POC shipped in weeks. Cortex guardrails were ready on day 1; no custom policy engine to build.</p>
</div>
<div class="section">
<h2>Expected Outcomes</h2>
<p><strong>Latency:</strong> Quote research from 5-30 minutes (email + manual lookup) → <1 minute (chatbot query)</p>
<p><strong>Scalability:</strong> 30+ salespeople can query the chatbot concurrently. Snowflake handles scale; dbt models are stateless (scale linearly).</p>
<p><strong>Governance:</strong> All discount exceptions flagged and audited. Policy violations are visible and traceable.</p>
<p><strong>Team capability:</strong> Once-daily batch + semantic layer pattern is reusable. Next use cases (contracts, pricing, serviceability) ship faster by leveraging the same playbook.</p>
</div>
<div class="section">
<h2>Learn More</h2>
<p>
See <code>README.md</code> for full narrative, decisions, and lessons learned.
Check <code>dbt/</code> for anonymized SQL models.
Review <code>cortex/cortex_governance_config.yaml</code> for guardrails and access control.
</p>
</div>
</div>
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<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Talk-to-Data Case Study</title>
<style>
@page{size:A4;margin:14mm}body{font-family:Arial,sans-serif;color:#1f2933;font-size:10pt;line-height:1.25}h1{color:#0b4f71;font-size:24pt;margin:0 0 2pt}h2{color:#0b4f71;font-size:13pt;margin:10pt 0 4pt;border-bottom:1px solid #b8c9d3;padding-bottom:2pt}p{margin:4pt 0}table{width:100%;border-collapse:collapse;margin:4pt 0 7pt;font-size:9pt}th{background:#0b4f71;color:#fff;text-align:left}th,td{border:1px solid #cbd5e1;padding:4pt;vertical-align:top}pre{background:#eef4f7;padding:6pt;border-left:3px solid #0b4f71;font-size:8pt}strong{color:#0b4f71}
</style>
</head>
<body>
<h1>Talk-to-Data</h1>
<p><strong>Governance-first semantic analytics for enterprise quotation workflows</strong></p>
<h2>The challenge</h2>
<p>More than 30 salespeople could depend on internal experts to answer routine quotation questions about products, discounts, and customer agreements. Manual lookup and email or chat coordination introduced an estimated <strong>530 minute delay per question</strong>.</p>
<h2>The approach</h2>
<p>Build a proof of concept around a curated semantic layer instead of exposing raw enterprise tables to an LLM.</p>
<pre>SAP ERP
│ daily batch
Snowflake raw → dbt staging → dbt transforms
Semantic views
Cortex guardrails & audit
┌────────┴────────┐
▼ ▼
Snowflake UI Internal chatbot</pre>
<h2>Architecture decisions</h2>
<table><tr><th>Decision</th><th>Why</th></tr>
<tr><td>Snowflake + Cortex</td><td>Fast POC path with data, AI, and governance in one platform.</td></tr>
<tr><td>dbt layers</td><td>Reproducible SQL, lineage, testing, and versioned business logic.</td></tr>
<tr><td>Semantic views</td><td>One business contract for dashboards and natural-language queries.</td></tr>
<tr><td>Daily refresh</td><td>Sufficient for quotation research; avoids premature real-time complexity.</td></tr>
<tr><td>Guardrails in data layer</td><td>Protection of personal and customer information, access control, freshness checks, and exception escalation are enforceable—not only prompt instructions.</td></tr></table>
<h2>Estimated outcome</h2>
<table><tr><th>Signal</th><th>Estimate</th></tr>
<tr><td>Routine answer latency</td><td><strong>530 min → &lt;1 min</strong></td></tr>
<tr><td>Sales users in scope</td><td><strong>30+</strong></td></tr>
<tr><td>Data freshness</td><td><strong>Daily batch</strong></td></tr>
<tr><td>Main benefit</td><td>Less coordination overhead and faster quote responses.</td></tr></table>
<p>These are <strong>estimates based on the human workflow</strong>, not measured production KPIs. The next delivery step is a controlled pilot that captures actual latency, adoption, escalation rate, and answer quality.</p>
<h2>Delivery lesson</h2>
<p>The reusable asset was not just the chatbot. It was the delivery pattern: establish the semantic contract, encode business rules, apply governance, and then expose the smallest useful interface.</p>
<p><strong>Stack:</strong> SAP source system · Snowflake · dbt · Snowflake semantic views · Cortex Analytics · internal chatbot workspace</p>
<p><em>All examples are anonymized and contain no proprietary source data.</em></p>
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# Talk-to-Data
## Governance-first semantic analytics for quotation workflows
### The challenge
More than 30 salespeople could depend on internal experts to answer routine quotation questions about products, discounts, and customer agreements. Manual lookup and email or chat coordination introduced an estimated **530 minute delay per question**.
### The approach
Build a proof of concept around a curated semantic layer instead of exposing raw enterprise tables to an LLM.
```text
SAP ERP
│ daily batch
Snowflake raw → dbt staging → dbt transforms
Semantic views
Cortex guardrails & audit
┌────────┴────────┐
▼ ▼
Snowflake UI Internal chatbot
```
### Architecture decisions
| Decision | Why |
|---|---|
| Snowflake + Cortex | Fast POC path with data, AI, and governance in one platform |
| dbt layers | Reproducible SQL, lineage, testing, and versioned business logic |
| Semantic views | One business contract for dashboards and natural-language queries |
| Daily refresh | Sufficient for the quotation research use case; avoids premature real-time complexity |
| Guardrails in the data layer | Protection of personal and customer information, access control, freshness checks, and exception escalation are enforceable—not only prompt instructions |
### Estimated outcome
| Signal | Estimate |
|---|---:|
| Routine answer latency | **530 min → <1 min** |
| Sales users in scope | **30+** |
| Data freshness | **Daily batch** |
| Main benefit | Less coordination overhead and faster quote responses |
These are **estimates based on the human workflow**, not measured production KPIs. The next delivery step is a controlled pilot that captures actual latency, adoption, escalation rate, and answer quality.
### Delivery lesson
The reusable asset was not just the chatbot. It was the delivery pattern: establish the semantic contract, encode business rules, apply governance, and then expose the smallest useful interface.
**Stack:** SAP source system · Snowflake · dbt · Snowflake semantic views · Cortex Analytics · internal chatbot workspace
*All examples are anonymized and contain no proprietary source data.*

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# Cortex Analytics Guardrails & Governance Configuration
# Semantic Layer: Quotation Analysis
# Purpose: Control data access, freshness, and output quality for LLM consumption
cortex_policies:
version: "1.0"
semantic_model: "sv_quotation"
# Data freshness contract: How fresh must data be for different use cases
freshness:
default_max_age_hours: 24
rules:
- use_case: "chatbot_quote_inquiry"
max_age_hours: 24
refresh_trigger: "daily_batch_08_00_utc"
description: "Daily batch refresh sufficient for quote research; cutoff 8am UTC (5am EST)"
- use_case: "real_time_dashboard"
max_age_hours: 2
refresh_trigger: "hourly"
description: "Sales team dashboard requires 2-hour freshness maximum"
# Access control: Who can query this semantic model
access_control:
default_role: "[REDACTED: SNOWFLAKE_ROLE]"
authorized_teams:
- name: "sales_team"
snowflake_role: "[REDACTED: SALES_ROLE]"
tables: ["sv_quotation", "sv_chatbot_quotation"]
max_rows_returned: 100000
- name: "operations_team"
snowflake_role: "[REDACTED: OPS_ROLE]"
tables: ["sv_quotation", "sv_chatbot_quotation"]
max_rows_returned: 500000
- name: "cortex_agent"
snowflake_role: "[REDACTED: CORTEX_AGENT_ROLE]"
tables: ["sv_chatbot_quotation"]
max_rows_returned: 1000
allowed_functions: ["semantic_search", "similarity_score"]
# LLM output guardrails: Control what the AI model can do with the data
llm_guardrails:
- rule: "discount_policy_redaction"
description: "Hide raw discount values from end users; show only 'within policy' or 'requires approval'"
pattern: "discount_.*_pct"
action: "redact_numeric_values"
replacement_logic: |
if discount_total_pct <= discount_ceiling_pct then
"Within policy"
else
"Requires manager approval"
end if
impact: "User sees governance status, not raw discount rules"
- rule: "customer_name_masking"
description: "Mask actual customer names in chatbot responses"
pattern: "customer_name|cliente_nome"
action: "mask_value"
replacement: "[REDACTED: Customer Information]"
exception: "Sales team in authorized_teams can see unmasked values"
- rule: "pii_scrubbing"
description: "Remove personally identifiable information (contact names, emails, phone)"
pattern: "sales_person|email|phone|contact_name"
action: "redact"
exception: "Internal sales team dashboard only"
- rule: "discount_exception_escalation"
description: "Flag when chatbot encounters discount above policy ceiling"
pattern: "requires_exception_approval = 1"
action: "escalate_to_human"
notification: "Send to operations team for manual review"
max_escalations_per_hour: 10
description: "Prevent bot from auto-approving exceptions"
# Quality gates: Validation rules before response generation
quality_gates:
- gate: "data_completeness"
check: "All required dimensions present (quote_id, material_id, customer_id)"
failure_action: "return_error_to_user"
error_message: "Quote data incomplete. Please provide quote number."
- gate: "data_staleness"
check: "Data age < freshness.max_age_hours"
failure_action: "warn_user"
warning_message: "Quote data may be up to 24 hours old."
- gate: "output_relevance"
check: "Cortex confidence score > 0.7 on semantic match"
failure_action: "escalate_to_human"
threshold_score: 0.7
description: "Only respond if model is confident about context"
# Cost controls: Prevent runaway LLM usage
cost_controls:
monthly_budget_usd: "[REDACTED: BUDGET]"
alert_threshold_pct: 80
per_query_max_tokens: 2000
max_concurrent_queries: 10
# Audit & compliance: Track all access and LLM decisions
audit:
log_level: "full"
events_logged:
- "user_query"
- "data_accessed"
- "llm_response_generated"
- "redaction_applied"
- "exception_escalated"
retention_days: 90
compliance_flags:
- "discount_policy_violation"
- "unauthorized_access_attempt"
- "data_freshness_breach"
semantic_model_lineage:
description: "How quotation data flows through transformations"
stages:
1_source:
system: "[REDACTED: SAP_SYSTEM]"
frequency: "Daily batch 05:00 UTC"
tables: ["[REDACTED: SOURCE_QUOTE_TABLE]", "[REDACTED: SOURCE_DISCOUNT_TABLE]"]
2_staging:
schema: "STAGING"
models: ["stg_quotes.sql", "stg_discount_conditions.sql"]
transformations: "Column renaming, type casting, null handling"
3_transform:
schema: "TRANSFORM"
models: ["trf_quotation.sql", "trf_chatbot_quotation.sql"]
transformations: "Discount calculation, portfolio mapping, governance flags"
4_semantic_layer:
schema: "DISTRIBUTE_DDL"
models: ["sv_quotation", "sv_chatbot_quotation"]
purpose: "Semantic views expose business logic, hide implementation details"
5_cortex_consumption:
interface_1: "Snowflake Native App (BI)"
interface_2: "[REDACTED: SIEMENS_WORKSPACE]"
llm_model: "[REDACTED: LLM_VERSION]"
prompt_template: |
You are a sales support assistant. Answer quote questions using only
the data provided. If discount exceeds policy, flag for human review.
Do not disclose raw discount rules.
notes:
- "This configuration enforces 'semantic layer first' — governance lives in data, not prompt engineering."
- "Redaction rules + access control + LLM guardrails work together: one fails, user sees safe fallback."
- "Cortex policies are version-controlled; audit trail shows all policy changes and who approved them."
- "Refresh schedule validates data freshness; chatbot rejects queries on stale data."

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# LinkedIn post draft
Sales teams should not need an email chain to answer a routine quotation question.
In a proof of concept, I designed a governance-first semantic analytics flow for quotation data:
**SAP → Snowflake → dbt → Semantic Views → Cortex → Chatbot**
The business problem was simple: more than 30 salespeople could need help validating a quote, discount, or product classification. A question that looked small could take 530 minutes because the answer depended on manual lookup and internal communication.
The solution was not “put an LLM on top of raw tables.”
I first created a semantic contract:
- curated quotation dimensions and facts;
- business-friendly synonyms for natural-language questions;
- centralized discount calculations;
- explicit policy-exception flags;
- lineage from source data to the consumer-facing model.
Then Cortex applied the controls around that contract:
- data freshness warning for the daily batch;
- role-based access;
- protection of sensitive information;
- escalation when a discount exceeded policy;
- audit logging for queries and decisions.
The semantic model was consumed in two ways:
1. Snowflake's interface for analytical exploration.
2. An internal chatbot workspace for direct questions, with prompt engineering to refine the response experience.
The estimated user outcome was reducing routine quote research from 530 minutes to less than one minute. That is an estimate based on the existing human workflow, not a production benchmark—and that distinction matters.
The main lesson: **governance belongs in the data and semantic layers, not only in the prompt.**
The POC also created a reusable delivery pattern for future use cases: define the business contract, expose only the right data, add guardrails, then choose the lightest useful interface.
I documented the anonymized architecture, decisions, and lessons learned here:
[GitHub repository link]
#DataArchitecture #Snowflake #dbt #DataGovernance #EnterpriseAI #TechnicalDelivery

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{{
config(
materialized='snowflake_semantic_view' )
}}
name: SV_CUSTOMER_QUOTATION_SEMANTIC
description: Semantic view for customer quotation analysis via AI-powered chatbot
tables:
- name: trf_quote_mart
description: Customer quotation items with product portfolio classification and sales team metadata. Designed for LLM consumption via chatbot and BI interfaces.
base_table: {{ ref('trf_quote_mart') }}
dimensions:
- name: quote_id
description: Unique quotation identifier. Links quotation header to line items.
expr: quote_id
data_type: TEXT
synonyms:
- quotation number
- quote number
- document number
- name: quote_line_item
description: Line item sequence within quotation.
expr: quote_line_item
data_type: TEXT
synonyms:
- item number
- line number
- name: portfolio_code
description: Product portfolio classification for grouping related offerings.
expr: portfolio_code
data_type: TEXT
synonyms:
- product category
- portfolio element
- offering type
- name: portfolio_name
description: Human-readable portfolio name (e.g., Data Integration, Automation, Security).
expr: portfolio_name
data_type: TEXT
synonyms:
- portfolio name
- offering name
- product line
- name: material_code
description: Product/service identifier. Maps to catalog in source system.
expr: material_code
data_type: TEXT
synonyms:
- product code
- material number
- SKU
- name: material_description
description: Product/service short name for quotation display.
expr: material_description
data_type: TEXT
synonyms:
- product description
- offering description
- name: customer_id
description: Customer account identifier.
expr: customer_id
data_type: TEXT
synonyms:
- customer code
- account number
- name: customer_name
description: Customer account name.
expr: customer_name
data_type: TEXT
synonyms:
- account name
- customer name
- name: sales_person
description: Sales representative responsible for quotation.
expr: sales_person
data_type: TEXT
synonyms:
- salesperson
- account owner
- representative
- name: quote_date
description: Quotation creation date.
expr: quote_date
data_type: TEXT
synonyms:
- creation date
- date
- issued date
facts:
- name: quantity
description: Quantity of product/service quoted.
expr: quantity
data_type: NUMBER
synonyms:
- qty
- volume
- name: net_value
description: Net value of quotation line item (after base pricing, before discounts).
expr: net_value
data_type: NUMBER
synonyms:
- price
- value
- amount
- name: discount_hierarchy_pct
description: Hierarchy-based discount percentage (based on customer category).
expr: discount_hierarchy_pct
data_type: NUMBER
synonyms:
- hierarchy discount
- tier discount
- name: discount_customer_pct
description: Customer-specific negotiated discount percentage.
expr: discount_customer_pct
data_type: NUMBER
synonyms:
- customer discount
- negotiated discount
- name: discount_agreement_pct
description: Agreement or contract-based discount percentage.
expr: discount_agreement_pct
data_type: NUMBER
synonyms:
- agreement discount
- contract discount
- name: discount_total_pct
description: Total applied discount across all conditions.
expr: discount_total_pct
data_type: NUMBER
synonyms:
- total discount
- effective discount
- name: discount_ceiling_pct
description: Maximum allowed discount policy ceiling.
expr: discount_ceiling_pct
data_type: NUMBER
synonyms:
- discount limit
- max discount
- LOA ceiling
- name: discount_above_ceiling
description: Percentage points of discount exceeding policy ceiling (governance flag).
expr: discount_above_ceiling
data_type: NUMBER
synonyms:
- above limit
- exception discount

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{{
config(
materialized='table',
database=target.database,
schema='transform',
tags=['semantic_layer', 'chatbot']
)
}}
with source_quotes as (
select
[REDACTED: quote_id column],
[REDACTED: line_item column],
[REDACTED: customer_id column],
[REDACTED: material_id column],
[REDACTED: quantity column],
[REDACTED: net_value column],
[REDACTED: quote_date column],
[REDACTED: sales_person_id column],
[REDACTED: source_timestamp column]
from [REDACTED: SOURCE_SCHEMA].[REDACTED: QUOTE_TABLE]
where [REDACTED: date_partition] >= dateadd(day, -1, current_date())
),
enrich_product_portfolio as (
select
sq.quote_id,
sq.line_item,
sq.customer_id,
sq.material_id,
sq.quantity,
sq.net_value,
sq.quote_date,
sq.sales_person_id,
/* Product portfolio classification */
case
when sq.material_id like '[REDACTED: pattern 1]%' then 'data-integration'
when sq.material_id like '[REDACTED: pattern 2]%' then 'automation'
when sq.material_id like '[REDACTED: pattern 3]%' then 'connectivity'
else 'other'
end as portfolio_code,
pm.portfolio_name,
pm.portfolio_category,
pm.material_description
from source_quotes sq
left join {{ ref('dim_product_master') }} pm
on sq.material_id = pm.material_id
),
calculate_discounts as (
select
epf.*,
/* Discount hierarchy: customer segment -> discount tier */
coalesce(cd.discount_tier_pct, 0) as discount_hierarchy_pct,
/* Customer-specific negotiated discount */
coalesce(cd.customer_discount_pct, 0) as discount_customer_pct,
/* Agreement-based discounts (volume, multi-year, etc.) */
coalesce(ca.agreement_discount_pct, 0) as discount_agreement_pct,
/* Maximum allowed discount (governance constraint) */
cd.discount_ceiling_pct,
/* Total discount calculation */
coalesce(cd.discount_tier_pct, 0) +
coalesce(cd.customer_discount_pct, 0) +
coalesce(ca.agreement_discount_pct, 0) as discount_total_pct
from enrich_product_portfolio epf
left join {{ ref('dim_customer_discount_policy') }} cd
on epf.customer_id = cd.customer_id
and epf.portfolio_code = cd.portfolio_code
left join {{ ref('fct_agreement_discounts') }} ca
on epf.customer_id = ca.customer_id
and epf.material_id = ca.material_id
),
governance_flags as (
select
cd.*,
/* Flag: discount exceeds policy maximum */
case
when cd.discount_total_pct > cd.discount_ceiling_pct
then cd.discount_total_pct - cd.discount_ceiling_pct
else 0
end as discount_above_ceiling,
/* Governance indicator: quote ready for human review */
case
when cd.discount_total_pct > cd.discount_ceiling_pct then 1
else 0
end as requires_exception_approval
from calculate_discounts cd
)
select
quote_id,
line_item,
customer_id,
material_id,
portfolio_code,
portfolio_name,
material_description,
quantity,
net_value,
discount_hierarchy_pct,
discount_customer_pct,
discount_agreement_pct,
discount_total_pct,
discount_ceiling_pct,
discount_above_ceiling,
requires_exception_approval,
quote_date,
sales_person_id,
current_timestamp() as dbt_loaded_at
from governance_flags
-- ponytail: materialized as table for chatbot + BI queries (not incremental yet; append-only refresh if needed later)