Rust Meets Serverless, Part 4: When Lambda Is the Wrong Tool
In Part 1, Part 2, and Part 3 I argued for Rust on Lambda and measured where the gains come from. This post draws the other edge of that fence: the shapes of work where Lambda is the wrong architectural choice, however lean the binary, and whichever language you wrote it in. The common thread across every case below is a single billing fact: Lambda charges you for wall-clock duration, including the time your handler spends waiting on IO. ...