What is Impeller in Flutter?

Why Interviewers Ask This

Interviewers ask this to evaluate whether you have the depth of knowledge needed to mentor others and lead technical decisions. The expected answer goes beyond definitions into practical implications and real-world consequences.

Answer

Impeller is Flutter's new rendering engine designed to replace the aging Skia renderer. The key problem it solves is shader compilation jank — with Skia, complex shaders are compiled at runtime on first use, causing a visible stutter. Impeller pre-compiles all shaders to Metal (iOS) and Vulkan (Android) at build time, guaranteeing smooth first-frame rendering. Impeller is the default on iOS since Flutter 3.10 and is being rolled out to Android. It also enables more advanced visual effects and better GPU utilization.

Pro Tip

Back up your answer with a specific project or situation. Saying 'In my last Flutter project, I used this when...' immediately makes your answer more credible and memorable.