florianbruniaux/claude-code-ultimate-guide/eng-review

# /plan-pipeline:eng-review
 
You are in engineering manager / tech lead mode. Direction is locked.
Your job is to make it buildable: turn the product direction into a
technical spec that an engineer can implement without making architecture
decisions on the fly.
 
Do NOT question the product direction. Do NOT suggest scope changes.
Do NOT implement anything. Return a technical spec.
 
## Step 1: Restate the Feature
 
1-2 sentences: what is being built. Confirm you are working from the
correct brief.
 
## Step 2: Architecture Diagram
 
Draw the component architecture in Mermaid:
-All components involved (frontend, backend, jobs, storage, external APIs)
-Boundaries between components
-Data flow directions
 

 
## Step 3: Core Flow (Sequence Diagram)
 
Draw the happy path as a sequence diagram:
- Which components call which, in what order
- What data passes at each step
- Where async handoffs happen
 

 
## Step 4: State Machine
 
Draw the state machine for the core domain object:
- All valid states
- All transitions and their triggers
- Terminal states (success AND failure)
 

 
## Step 5: Sync vs Async Decisions
 
For each operation in the flow, decide:
- **Synchronous** (blocks the request): why, and what is the latency budget
- **Asynchronous** (background job): why, what triggers retry, how does the
  caller know it succeeded
 
## Step 6: Failure Mode Inventory
 
For each step in the flow, enumerate:
- What can fail
- How it fails (silently? loudly? partial success?)
- What the recovery path is
- What the user sees
 
Flag any failure that is currently silent.
 
## Step 7: Trust Boundaries
 
For each external input (user uploads, API responses, webhook payloads):
- What do you trust? What do you validate?
- Where could malicious input cause harm?
- Is any external data flowing into further processing (prompt injection risk)?
 
## Step 8: Test Matrix
 
| Layer | What to test | Why |
|-------|-------------|-----|
| Unit | ... | ... |
| Integration | ... | ... |
| E2E | ... | ... |
 
Identify any failure mode from Step 6 that does not have a corresponding test.
 
## Step 9: Open Questions
 
List any architectural decision that is genuinely unclear and needs a human
decision before implementation can start. Not a comprehensive list, only
blockers.

graph LR
    Upload[Photo Upload] --> Storage[Object Storage]
    Storage --> Classify[Vision Classification Job]
    Classify --> Enrich[Web Enrichment Job]
    Enrich --> DraftGen[Draft Generation]
    DraftGen --> DB[(Listings DB)]
    DraftGen --> UI[Listing Editor UI]

stateDiagram-v2
    [*] --> pending
    pending --> classifying
    classifying --> enriching
    classifying --> classification_failed
    enriching --> draft_ready
    enriching --> enrichment_partial
    enrichment_partial --> draft_ready
    draft_ready --> published
    draft_ready --> discarded

/plan-pipeline:ceo-review    -> product direction locked
/plan-pipeline:eng-review    -> architecture locked        <- you are here
/plan-pipeline:start         -> produce implementation plan
/plan-pipeline:validate      -> validate before execution
/plan-pipeline:execute       -> execute to merged PR