Frontend System Design Essentials: Optimistic updates

👉 Frontend System Design Essentials — Course (Now Available): https://icodeit.thinkific.com/courses... 👉 Frontend System Design Essentials — Book: https://leanpub.com/frontend-system-d... Most UI interactions work — but don’t always feel responsive. Whether you're submitting a comment, tapping "like," or updating a list, even a short delay can make your app feel slow and unpolished. That’s where optimistic updates come in — a technique that lets you update the UI before the server responds, creating a snappier, more seamless experience for users. In this video, I walk you through the idea of optimistic updates in frontend development — what they are, when to use them, and how to implement them using React Query with a REST API. This is another episode in the Frontend System Design Essentials series — each video focuses on one key concept that helps you build responsive, scalable, and maintainable frontend systems. In this episode, you’ll learn how to: Understand the UX problem caused by even small delays in feedback Use optimistic updates to make likes and comments feel instant Handle errors with rollback and restore the original state Implement this pattern using React Query’s onMutate, onError, and onSuccess By the end, you’ll have a solid, practical understanding of optimistic updates — and how to use them to build fast, delightful user interfaces. [MY BOOKS & COURSES] 👉 Frontend System Design Essentials: https://leanpub.com/frontend-system-d... 👉 React Data Fetching Patterns: https://leanpub.com/react-data-fetchi... 👉 Maintainable React (Udemy Course): https://udemy.com/course/mastering-ma... 👉 React Anti-Patterns (Amazon): https://www.amazon.com/dp/1805123971 👉 More Tutorials on Advanced Patterns: https://icodeit.com.au/tutorials/adva... [STAY CONNECTED] 🧠 Newsletter (system design & clean code): https://juntao.substack.com/ 🌐 Website & Blog: https://icodeit.com.au/ 🐦 Twitter / X:   / juntaoqiu   📺 YouTube (subscribe):    / @icodeit.juntao   💬 Let me know in the comments: Have you used optimistic updates before? What’s your favorite place to apply them — likes, checkboxes, or comment forms? #frontend #systemdesign #reactjs #optimisticupdate #userexperience #icodeit