Schedulers

Lesson in the iOS Roadmap · Stage 16: Delegate Pattern

Last updated 14 September 2026

What is Schedulers?

Schedulers in RxSwift control on which thread or queue Observable work executes. MainScheduler runs work on the main thread for UI updates, while ConcurrentDispatchQueueScheduler and SerialDispatchQueueScheduler run work on background queues. The observeOn and subscribeOn operators specify which scheduler handles observation and subscription respectively.

Study this in the interactive course See the whole iOS roadmap

Free resources to learn Schedulers

Official docsReactiveX Scheduler Documentation
Open sourceRxSwift Scheduler Documentation
ArticleRxSwift Schedulers

Schedulers: common questions

Can I learn Schedulers in Hindi?

This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Schedulers in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.

Is this Schedulers tutorial for beginners?

It is lesson 100 of 170 in the free iOS roadmap, in stage 16, Delegate Pattern. If you are new to iOS, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.