Book: The TypeScript Type System — From Generics to DSL-Level Types Also by me: The TypeScript Library — the 5-book collection My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub You picked Zod three years ago and never looked back. The schemas validate, the types infer, your team knows it. Then someone links an ArkType benchmark page showing it parses several times faster than Zod on a nested object. A frontend teammate replies that Valibot trims their auth bundle from 17.7KB to 1.37KB on the same login form. You wonder if you've been wrong this whole time. Defaulting to Zod was a fine call. It is also worth a second look now that v4 is out and the alternatives have grown up. The three libraries solve the same surface problem: runtime validation that infers static types. They get there with three completely different type-system mechanics. Zod 4 builds a class hierarchy with chainable methods.…