In Chrome M117 we introduced a new optimizing compiler: Maglev. Maglev sits between our existing Sparkplug and TurboFan compilers, and fills the role of a fast optimizing compiler that generates good enough code, fast enough. Background # Until 2021 V8 had two main execution tiers: Ignition, the interpreter; and TurboFan, V8’s optimizing compiler focused on peak performance. All JavaScript code is