Phase 2 — Networking, Protocols & Concurrency

Every backend database call, Redis lookup, webhook, and browser request is bytes moving over a kernel socket. Phase 2 strips away the magic of web frameworks so you understand TCP state machines, DNS/TLS, HTTP/1.1–3, Server-Sent Events (SSE), OS threads vs processes, and the asyncio event loop.

Modules & Lessons

01 — Network Fundamentals & Protocols

• 01-tcp-udp-and-sockets — OSI/TCP-IP model, 3-way handshake, TCP state machine, TIME_WAIT, keepalives, and raw Python sockets
• 02-dns-tls-and-reverse-proxies — DNS resolution, TLS 1.3 handshake, certificates, and reverse proxy mechanics (Nginx/Caddy)
• 03-http-evolution-and-semantics — HTTP/1.1 vs HTTP/2 vs HTTP/3, methods, idempotency, caching headers (ETag), and status codes
• 04-realtime-sse-and-websockets — Short/long polling, Server-Sent Events (SSE), WebSockets, and connection lifecycle management

02 — Concurrency, Parallelism & Asyncio

• 01-threads-processes-and-gil — OS threads vs processes, the Python GIL, CPU-bound vs I/O-bound workloads, and concurrent.futures
• 02-synchronization-and-locks — Race conditions, deadlocks, Lock, RLock, Semaphore, Event, and thread-safe queues
• 03-asyncio-event-loop-internals — Coroutines, event loop scheduling, non-blocking sockets (epoll), and the golden rule: never block the loop
• 04-structured-concurrency-and-backpressure — TaskGroup, cancellation, timeouts, asyncio.Semaphore, and graceful server shutdown

Capstone Milestone: pulseforge/ v0.3

Add an asynchronous TCP/HTTP event ingestion server to PulseForge featuring bounded asyncio.Queue backpressure, real-time live tailing over Server-Sent Events (SSE), and zero-drop graceful shutdown on SIGTERM.