Dart Concurrency Complete Guide — Isolates, compute, Streams, and Mutex Patterns Most Flutter UI jank ultimately comes from blocking the main thread with heavy computation. Dart's concurrency model is powerful but often misunderstood. This guide covers every tool in the toolkit — from the ergonomic compute() shortcut to zero-copy buffer transfers and synchronized mutexes. Dart's Single-Threaded Model and the Event Loop Dart runs on a single thread by default. Asynchronous code ( async / await ) doesn't create parallelism — it just yields control to the event loop while waiting for I/O, then resumes. Two pieces of Dart code never truly run simultaneously on the main thread. The critical distinction: Async (async/await) : Cooperative concurrency — efficient for I/O-bound work, but still single-threaded. Isolates : True parallelism on a separate OS thread — required for CPU-bound work.…