Book: The Complete Guide to Go Programming Also by me: Thinking in Go (2-book series) — Complete Guide to Go Programming + Hexagonal Architecture in Go My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub Open internal/util/slice.go in any Go service that was bootstrapped before 1.21. You'll find ContainsString , IndexOfInt , a hand-rolled removeAt , two versions of uniq , and a mergeSlices helper that someone copy-pasted from Stack Overflow in 2019. Most of that file can go. Go 1.21 shipped the slices package in August 2023, and 1.22 filled in the last gap with Concat . Eleven of those functions cover the work those helpers were doing. The migration is mechanical: import "slices" , delete the helper, replace the call. There's one catch worth knowing before you swap. Delete and Compact quietly changed behavior between 1.21 and 1.22 in a way that affects pointer-heavy slices.…