/Go Engineering/Phase 7

Phase 7Days 31-35

HTTP APIs with the Standard Library

net/http, middleware, JSON contracts, validation, shutdown, and observability

Phase Goal

Build production-shaped APIs using net/http before adopting frameworks.

Progress

Notes

Open the written lectures for this course before checking off the phase topics.

Projects

Community Tool Library API

Day 31: HTTP Mental Model & net/http

Define Request-response lifecycle and HTTP semantics in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Request-response lifecycle and HTTP semantics is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Request-response lifecycle and HTTP semantics and fix it deliberately

Define ServeMux patterns and method-aware routes in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when ServeMux patterns and method-aware routes is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for ServeMux patterns and method-aware routes and fix it deliberately

Define Handlers, ResponseWriter commit behavior, and headers in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Handlers, ResponseWriter commit behavior, and headers is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Handlers, ResponseWriter commit behavior, and headers and fix it deliberately

Define Server timeouts and explicit configuration in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Server timeouts and explicit configuration is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Server timeouts and explicit configuration and fix it deliberately

Day 32: JSON APIs, Validation & Errors

Define Decode limits and unknown-field rejection in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Decode limits and unknown-field rejection is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Decode limits and unknown-field rejection and fix it deliberately

Define Transport/domain separation and validation in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Transport/domain separation and validation is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Transport/domain separation and validation and fix it deliberately

Define Consistent problem response envelopes in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Consistent problem response envelopes is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Consistent problem response envelopes and fix it deliberately

Define Status-code decisions and idempotent semantics in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Status-code decisions and idempotent semantics is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Status-code decisions and idempotent semantics and fix it deliberately

Day 33: Middleware, Logging & Request IDs

Define Middleware as handler composition in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Middleware as handler composition is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Middleware as handler composition and fix it deliberately

Define Panic recovery boundaries in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Panic recovery boundaries is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Panic recovery boundaries and fix it deliberately

Define Structured logging, request IDs, and redaction in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Structured logging, request IDs, and redaction is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Structured logging, request IDs, and redaction and fix it deliberately

Define CORS, rate-limit placement, and trust proxies in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when CORS, rate-limit placement, and trust proxies is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for CORS, rate-limit placement, and trust proxies and fix it deliberately

Day 34: Clients, Context & Graceful Shutdown

Define Configured http.Client and connection reuse in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Configured http.Client and connection reuse is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Configured http.Client and connection reuse and fix it deliberately

Define Context propagation through outbound calls in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Context propagation through outbound calls is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Context propagation through outbound calls and fix it deliberately

Define Signals, Server.Shutdown, and draining work in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Signals, Server.Shutdown, and draining work is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Signals, Server.Shutdown, and draining work and fix it deliberately

Define Health, readiness, and dependency checks in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Health, readiness, and dependency checks is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Health, readiness, and dependency checks and fix it deliberately

Day 35: Mini Project — Community Tool Library API

Define Tool, member, loan, and maintenance state contracts in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Tool, member, loan, and maintenance state contracts is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Tool, member, loan, and maintenance state contracts and fix it deliberately

Define Validated JSON, middleware, logs, and request IDs in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Validated JSON, middleware, logs, and request IDs is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Validated JSON, middleware, logs, and request IDs and fix it deliberately

Define Graceful shutdown and httptest coverage in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Graceful shutdown and httptest coverage is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Graceful shutdown and httptest coverage and fix it deliberately

Define Project requirements, OpenAPI, and operator README in plain language and explain the problem it solvesTrace what the Go compiler or runtime does when Project requirements, OpenAPI, and operator README is usedWrite a tiny example, then apply it to a realistic backend taskDiagnose the beginner failure mode for Project requirements, OpenAPI, and operator README and fix it deliberately

Capstone

Community Tool Library API

Build an in-memory standard-library API for librarians to register tools, issue and return loans, quarantine damaged equipment, and expose a privacy-safe public catalog.

net/http only with explicit server limits
Illegal loan and maintenance transitions rejected
httptest coverage, request tracing, and graceful shutdown

Phase Complete!

After this phase, you'll be able to:

Request-response lifecycle and HTTP semantics
ServeMux patterns and method-aware routes
Handlers, ResponseWriter commit behavior, and headers
Server timeouts and explicit configuration
Decode limits and unknown-field rejection
Transport/domain separation and validation
Consistent problem response envelopes
Status-code decisions and idempotent semantics

You can apply Phase 7 skills in a finished, explainable Go project.

Back to all phases

Phase Goal

Day 31: HTTP Mental Model & net/http

Request-response lifecycle and HTTP semantics

ServeMux patterns and method-aware routes

Handlers, ResponseWriter commit behavior, and headers

Server timeouts and explicit configuration

Day 32: JSON APIs, Validation & Errors

Decode limits and unknown-field rejection

Transport/domain separation and validation

Consistent problem response envelopes

Status-code decisions and idempotent semantics

Day 33: Middleware, Logging & Request IDs

Middleware as handler composition

Panic recovery boundaries

Structured logging, request IDs, and redaction

CORS, rate-limit placement, and trust proxies

Day 34: Clients, Context & Graceful Shutdown

Configured http.Client and connection reuse

Context propagation through outbound calls

Signals, Server.Shutdown, and draining work

Health, readiness, and dependency checks

Day 35: Mini Project — Community Tool Library API

Tool, member, loan, and maintenance state contracts

Validated JSON, middleware, logs, and request IDs

Graceful shutdown and httptest coverage

Project requirements, constraints & review

Community Tool Library API

Phase Complete!