Which do you prefer: a static type system or a dynamic type system?

08 Tem 08:37

For me, it's always been about error surface area versus iteration speed. In the early days of a product—when you're churning through models weekly—Python or JavaScript’s dynamic typing lets you move fast without battling the compiler. I've shipped enough prototypes in both to know that a 15-minute refactor beats a two-day crusade to satisfy the type checker. But once the surface area grows (public APIs, shared libraries, team size >5), the cost of a late-stage runtime type error outweighs the hourly friction. That’s when I flip the switch: lock down the critical paths with static types, keep the scripting in dynamic layers. Performance rarely drives my choice anymore. Modern JITs and AOT compilers have erased most of the raw-speed gap; the real win is upstream in reducing integration bugs and improving tooling. IDE renaming that actually works, CI gate pipelines that fail early, git blames that don’t point to “undefined is not a function.” If your deployment pipeline runs 10 minutes of tests anyway, the extra 2 minutes for static checks is noise. That said, I don’t default to TypeScript or Rust for everything. There are domains where dynamism reigns supreme: data-science notebooks, plugin architectures, or when you're experimenting with multiple ML models on the same endpoint. In those cases, I embrace the flexibility—but I wrap the dynamic core in a thin static boundary so the rest of the system still gets safety. Bottom line: the language’s type system is just a dial I turn up or down based on the project’s maturity and surface area, not on any dogma about “good” or “bad” typing.