Day 7: Week 17 Mini-Project — Production FastAPI Streaming Copilot Microservice

1. Project Overview

In this Week 17 Mini-Project, we unite all 6 days of high-concurrency backend engineering into a single, cohesive, production-grade FastAPI Streaming SRE Copilot Microservice:

2. Integrated Capabilities

1. ASGI Lifespan & Config Management (Day 1): Loads universal .env variables and initializes shared app state.
2. Server-Sent Events (text/event-stream) (Day 2): W3C-compliant token chunk streaming with thought annotations and disconnect prevention.
3. Multi-Turn Chat Memory (Day 3): Tracks user conversation sessions and enforces rolling context window budgets.
4. Tenant Security & Token-Bucket Rate Limiter (Day 4): Enforces RPM bursts and hard daily dollar spend caps.
5. Asynchronous Background Processing (Day 5): Dispatches audit records and HMAC-signed webhook payloads without blocking the token stream.
6. Telemetry & Health Probes (Day 6): Exposes /healthz and /metrics reporting p50, p95 latency and token consumption stats.

In Simple English: Week 17 Streaming FastAPI Copilot Walkthrough

Open Tab 2 (Codes) and Tab 4 (Test & Troubleshooting) to inspect and verify the production streaming service architecture tying Week 17 together:

• Non-blocking async SSE streaming (TTFT-first delivery)
• Token-bucket per-tenant rate limiter (HTTP 429 protection)
• Background audit logging + P95 latency instrumentation!