In this release of tiny, the JobComponentSystem API is supported, but its implementation is not multithreaded. When you schedule a job, we immediately execute it. This is how we will run in single-threaded environments, like the web is (today. multithreading might come to the web in an "on by default" way). We are working on making it so that when you use tiny to target a multi-thread capable environment, it uses multithread implementation of the job system. Burst will work in both scenarios.