Yep, try/catch is optimized since node v8. The biggest takeaway from the latest batch of optimizations I read about is this: Write idiomatic JavaScript code!

Yep, try/catch is optimized since node v8. The biggest takeaway from the latest batch of optimizations I read about is this: Write idiomatic JavaScript code! Secondly: Just because you're working with a dynamic language doesn't mean you should abuse it. Don't write functions with weirdly changing parameter arities, or dynamically change the types of variables. Finally: These things are all hints and micro-optimizations by themselves. Don't prematurely optimize at the cost of readability and maintenance. Profile and only fix things that need fixing!