# Lesson 1 complete + OMT primary sources read

Learner finished lesson 1 (when workers fit) and read web.dev off-main-thread, MDN Web Workers material, and Surma’s “When should you be using Web Workers?”. Treat choose/reject framing, OMT resilience (work moves, doesn’t vanish), and dedicated vs service-worker distinction as established. Next ZPD: dedicated-worker lifecycle and the messaging contract (create → message → error → terminate/close).