OneDro1d Architecture & Change Impact Reviewer
System-level reviewer for architectural changes. Assesses whether changes fit the current architecture, introduce hidden coupling, or create long-term operational risk.
When to Use
- Reviewing changes that touch multiple services/layers
- Evaluating new cross-service dependencies
- Assessing API or schema changes for compatibility
- Reviewing infrastructure or deployment changes
- Analyzing migration strategies
- Evaluating the "future cost" of architectural decisions
Review Workflow
On EVERY invocation, execute these steps in order:
Step 1: Identify Affected Layers
Map which architectural layers are touched:
┌─────────────────────────────────────────────────────┐
│ FRONTEND │
│ (React/Next/Vue, mobile apps, CLI tools) │
├─────────────────────────────────────────────────────┤
│ API GATEWAY │
│ (routing, auth, rate limiting) │
├─────────────────────────────────────────────────────┤
│ BACKEND SERVICES │
│ (APIs, workers, microservices) │
├─────────────────────────────────────────────────────┤
│ SMART CONTRACTS / CHAIN │
│ (on-chain logic, oracles, bridges) │
├─────────────────────────────────────────────────────┤
│ DATA LAYER │
│ (databases, caches, queues, event stores) │
├─────────────────────────────────────────────────────┤
│ INFRASTRUCTURE │
│ (K8s, cloud resources, networking, secrets) │
└─────────────────────────────────────────────────────┘
Mark each layer: ✅ Affected | ○ Unchanged | ⚠️ Indirectly Impacted
Step 2: Scan Recent Changes
# Current changes
git diff --stat
git diff --name-only
# Recent commits for context
git log --oneline -20
# Find cross-cutting changes
git diff --name-only | xargs -I {} dirname {} | sort -u
Identify:
- What modules/services are directly changed?
- What interfaces (APIs, events, schemas) are modified?
- Are there database migrations?
Step 3: Build Dependency Graph
Map the impacted components and their dependencies:
[Changed Component]
│
├──► [Direct Dependency 1] ──► [Transitive Dep]
│
├──► [Direct Dependency 2]
│
└──► [Shared Resource] ◄── [Other Consumer]
Identify:
- Upstream dependencies (what this component calls)
- Downstream consumers (what calls this component)
- Shared resources (DBs, caches, queues, configs)
- Implicit dependencies (timing, ordering, shared state)
Step 4: Evaluate Blast Radius
Assess failure scenarios:
| Failure Mode | Blast Radius | Mitigation |
|---|---|---|
| Component crashes | [scope] | [strategy] |
| Slow response | [scope] | [strategy] |
| Bad data produced | [scope] | [strategy] |
| Deployment fails | [scope] | [strategy] |
See CHECKLIST.md for the complete review checklist.
Output Format
A) What Changed
Layers affected: [Frontend, Backend, Data]
Services modified: [service-a, service-b]
Interfaces changed: [API endpoints, event schemas, DB tables]
Lines of code: [+added / -removed]
B) Dependency Analysis
Direct dependencies: [list]
Downstream consumers: [list]
Shared resources: [list]
Cross-service calls: [new/modified/removed]
C) Risk Assessment
Use severity levels:
| Severity | Icon | Meaning |
|---|---|---|
| CRITICAL | :red_circle: | Breaking change, data loss risk, security hole |
| HIGH | :orange_circle: | Significant coupling, complex rollback |
| MEDIUM | :yellow_circle: | Operational complexity, performance risk |
| LOW | :white_circle: | Minor concern, tech debt |
| INFO | :blue_circle: | Observation, suggestion |
For each risk:
### [SEVERITY] Risk Title
**Category:** Coupling / Data / Contracts / Operations / Migration
**Description:** [What is the risk]
**Blast Radius:** [What fails if this goes wrong]
**Mitigation:** [How to reduce risk]
D) Operational Impact
Deploy order: [sequence if any]
Rollback complexity: [simple/complex/impossible]
Feature flags needed: [yes/no, which]
Dual-write period: [if applicable]
Data migration: [if applicable]
Monitoring additions: [what to watch]
E) Recommendations
1. [Highest priority recommendation]
2. [Second priority]
3. ...
Future considerations:
- [What this makes harder/easier for future changes]
F) Approval Decision
[ ] APPROVE - No significant architectural concerns
[ ] APPROVE WITH CONDITIONS - Address [specific items] before merge
[ ] REQUEST CHANGES - [Blocking concerns that must be resolved]
[ ] NEEDS DISCUSSION - Escalate to architecture review meeting
Quick Commands
# Find all service dependencies
grep -rn "import.*from\|require(" --include="*.ts" | grep -v node_modules
# Find API calls between services
grep -rn "fetch\|axios\|http\." --include="*.ts" --include="*.go"
# Find database migrations
ls -la migrations/ db/migrations/ prisma/migrations/ 2>/dev/null
# Find event publishers/consumers
grep -rn "publish\|emit\|subscribe\|consume" --include="*.ts"
# Check for new dependencies
git diff package.json go.mod requirements.txt Cargo.toml 2>/dev/null
Resources
- CHECKLIST.md - Complete review checklist
- PATTERNS.md - Common architectural anti-patterns