Project Structure & Dependency Map

File Hierarchy

16-rate-limit-gateway/
├── apps/
│   ├── gateway/                # Node.js Express 5 Gateway Entrypoint
│   └── web/                    # React 19 Vite Admin Monitoring Console
├── packages/
│   ├── core/                   # Core types, interfaces, and clock abstractions
│   ├── aiml/                   # DDoS & anomaly detection model wrappers
│   ├── control-plane/          # Admin configuration & dynamic policy endpoints
│   ├── obs/                    # OpenTelemetry metrics & structured logging
│   ├── oracle/                 # Anomaly scoring & adaptive threshold oracle
│   ├── security/               # API key validation, JWT inspection, CIDR filtering
│   ├── store-memory/           # Lock-free in-memory bucket store (fallback)
│   ├── store-redis/            # Atomic Redis Lua script engine & connection pool
│   └── testutil/               # Mock clocks, synthetic traffic generators
├── src/                        # Core TypeScript engine (algorithms, identity, policy)
│   ├── algorithms/             # Token bucket, leaky bucket, sliding window
│   ├── gateway/                # Express middleware & rate limiter handler
│   ├── identity/               # Client key extraction & fingerprinting
│   ├── policy/                 # Rule engine & route cost resolver
│   └── store/                  # Storage contract & memory/redis adapters
├── tests/                      # 25 Vitest test suites (P0 core, resilience, security)
├── package.json                # Monorepo workspaces configuration
└── docker-compose.yml          # Gateway, Redis, and Prometheus stack

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Tech Stack & Runtime Dependencies

Tier	Technology	Version	Purpose
Runtime	Node.js	v22+	Non-blocking event-driven JavaScript runtime
Language	TypeScript	5.8.3	End-to-end static typing across monorepo
HTTP Framework	Express	5.3.0	Modern async-native HTTP routing engine
Storage Engine	Redis / ioredis	5.6.1	Atomic distributed counters via Lua scripting
Validation	Zod	4.6.7	Strict runtime schema parsing for policy configs
Property Testing	Fast-Check	4.10.2	Property-based fuzzing of rate-limit window boundaries
Test Runner	Vitest	2.1.8	High-speed ESM unit and integration test runner