Lumen is benchmarked at 100/rps (Requests Per Second) faster than Slim v3, which used to be considered the fastest and most performant micro-Framework to date with the ability to handle 1800/rps. (1900/rps vs 1800/rps respectively).
Since it's basically just a minimal version of Laravel, it can be upgraded to a full Laravel app if the need arises. No need for code changes, just import the code to a new Laravel install.