Tier này dạy gì?
Tier 3 là phần "đi sâu" của Go: generics (Go 1.18+),
reflect runtime, escape analysis & GC tri-color, pprof profiling,
benchmark đúng cách, các pattern concurrency thực chiến, và idioms thiết kế Go.
Kết thúc bằng mini-project web scraper concurrent có rate limit + context cancel.
Tiền đề: đã xong Tier 2 (đặc biệt L27 channel, L29 context).
Lesson 30
Type parameters, constraints, comparable, any, khi nên/không nên dùng.
Lesson 31
reflect.TypeOf/ValueOf, walk struct, dynamic dispatch, performance cost.
Lesson 32
unsafe.Pointer, struct layout manipulation, gọi C qua CGo.
Lesson 33
Stack vs heap, escape analysis (-gcflags=-m), GC tri-color, GOGC tuning.
Lesson 34
CPU/mem/block/goroutine profile, flamegraph, tìm real bottleneck.
Lesson 35
testing.B, benchstat, b.ReportAllocs(), micro-bench pitfall, real-world optimization.
Lesson 36
Worker pool, fan-in/out, pipeline, semaphore, errgroup, singleflight.
Lesson 37
Fuzz testing, race, integration test, golden file, testcontainer.
Lesson 38
Interface for testing, generate mock với mockgen/mockery, DI patterns.
Lesson 39
Functional options, accept interface return struct, composition over inheritance, builder.
Lesson 40
Error tree, structured error, recoverable vs fatal, retry pattern.
Lesson 41
Build web scraper concurrent có rate limit + context cancel + retry + result aggregation.