Learning objectives
By the end of this module, you should be able to:
- Assemble one coherent AI architecture with explicit trust boundaries and fallbacks.
- Produce evaluation, security and operational evidence sufficient to defend a release decision.
- Explain residual risk and what evidence would trigger rollback or human escalation.
The capstone is about connected evidence
A polished chat UI is not sufficient. The deliverable must show how the user contract flows into retrieval, model/tool policy, evaluation gates, security controls and runtime observability.
Promotion is a decision, not a demo
State the baseline and candidate, blocking eval slices, operational budgets, unresolved risks and rollback/fallback plan. If evidence is insufficient, 'do not promote' is a valid engineering outcome.
Trust boundaries must be visible
Label user input, retrieved data, model output and tool proposals as untrusted until validated. Show where document authorization, user authorization and human approval occur.
Evaluation must include adversarial and abstention cases
A capstone that tests only answerable happy paths cannot demonstrate production readiness.
Operations must be diagnosable
Show what trace/metric evidence would tell an on-call engineer whether a failure is retrieval, model inference, tool execution, validation, capacity or policy.
Residual risk belongs in the design
Document what the system does not guarantee and where humans remain responsible. World-class engineering is explicit about limits.
Worked examples
Capstone evidence chain
application contract
→ model/routing decision
→ prompt/context contract
→ retrieval + citations
→ structured output / tools
→ eval baseline + candidate
→ threat model + guardrails
→ telemetry + SLO/fallback
→ PROMOTE | HOLD | ROLLBACK
- Every arrow must be supported by an artifact or test.
Minimum release record
model/runtime identity
prompt/config version
retrieval/index version
eval dataset version + results
security critical-slice results
latency/capacity evidence
known limitations
rollback/fallback owner
- This is the evidence needed to explain a future regression.
Try it · core lab · account-free
Lab 12 — Build and defend the Atlas Assist release candidate
Goal: Produce a small production-shaped evidence pack and run the bundled validator.
Before you start
- No paid API or cloud account is required for the core lab.
- Core labs use Python 3 and local files only.
- Running case: you are engineering 'Atlas Assist', an internal support assistant over a small approved knowledge base with one read-only inventory tool.
- Carry requirements, eval cases, threat assumptions and operational evidence forward across modules instead of starting over.
STEP 1Download/extract the lab pack
rm -rf /tmp/atlas-ai-capstone && mkdir -p /tmp/atlas-ai-capstone
unzip -q public/labs/ai/AI-Engineering-Lab-Pack-v0.3.19-r2.zip -d /tmp/atlas-ai-capstone
find /tmp/atlas-ai-capstone -maxdepth 2 -type f | sort
STEP 2Create your release decision
Complete capstone/release-decision.json with model route, fallback, eval thresholds, security blockers, operational budget and PROMOTE/HOLD/ROLLBACK decision.
STEP 3Run validator
python3 /tmp/atlas-ai-capstone/capstone/validate_release.py /tmp/atlas-ai-capstone/capstone/release-decision.json
STEP 4Defend the decision
Write 200–300 words explaining the highest residual risk, why your eval set is representative enough for this stage, and which production signal would trigger rollback or human escalation.
Verify
- The release decision references evaluation, security and operational evidence.
- Fallback and rollback preserve authorization/evidence constraints.
- The design distinguishes model output from trusted application decisions.
Expected outcome
- A defensible AI release evidence pack and explicit promotion decision.
Break / fix · diagnose
- If the validator passes but your evidence is weak, HOLD is still the correct decision.
- If the design cannot say what happens when retrieval/model/tool is unavailable, add a fallback before promotion.
Production viewProduction AI systems need the same disciplined release evidence as other critical software, plus explicit evaluation of variable model behaviour.
Local real-tool practicum · optional but recommended
Optional practicum — end-to-end local evidence run
Use an approved local chat model and embedding model to generate real outputs for the capstone eval set, while keeping the deterministic validator as the policy gate.
Prerequisites
- Ollama installed and reachable on http://127.0.0.1:11434 for the real-tool path.
Resources created
- Only local disposable files/processes used by the practicum.
Cost / risk
- No cloud account required; model downloads consume disk and network bandwidth.
TOOL 1MODEL=${MODEL:-qwen3:8b}; EMBED_MODEL=${EMBED_MODEL:-embeddinggemma}; echo "chat=$MODEL embed=$EMBED_MODEL"
TOOL 2curl -fsS http://127.0.0.1:11434/api/version
TOOL 3python3 /tmp/atlas-ai-capstone/evals/evaluate.py /tmp/atlas-ai-capstone/evals/sample-results.jsonl
Verify
- You can attach model/runtime identity and eval output to the release evidence without changing the decision contract.
Cleanup
- Remove only the disposable files created for the lab; keep model caches only if you intend to reuse them.
Warnings
- A local model run is optional and hardware-dependent; the certificate assessment must not require a specific vendor/model or GPU.
Capstone rubric
Score connected engineering evidence—not UI polish.
Application contract & architecture · 20%
User task, evidence boundary, output/fallback contract and labelled trust boundaries.
Retrieval & grounding · 15%
Measured retrieval cases, source attribution, missing/conflicting evidence behaviour.
Tools & workflow safety · 15%
Bounded tools, authorization, idempotency/stop rules and approval points.
Evaluation & regression · 20%
Representative dataset, baseline/candidate results, critical slices and decision thresholds.
Security & governance · 15%
Threat model, data minimization, injection/tool/output controls and residual risk.
Operations & release decision · 15%
Telemetry/SLO/cost/fallback evidence plus PROMOTE/HOLD/ROLLBACK rationale.
Avoid these traps
Common mistakes
- Treating the capstone validator as proof of production safety.
- Using only happy-path evaluation cases.
- Leaving tool authorization or document access implicit.
- Shipping without explicit rollback/fallback and residual-risk ownership.
Knowledge check
Can you connect the AI behaviour to a system control?
Concept and scenario checks. Reveal the answer only after you commit to a decision.
1What makes the capstone production-shaped?
It connects contract, evidence, evaluation, security, operations and a release decision rather than demonstrating isolated model output.
2Is HOLD a valid capstone outcome?
Yes, when evidence does not meet the defined promotion contract.
3What must remain outside model authority?
Security/authorization, release policy, hard budgets and high-impact approval decisions.
4Scenario: all functional evals pass but the critical injection slice fails. What is the release decision?
HOLD or rollback according to policy; critical security slices block promotion despite functional success.