Frontend System Design Essentials: Frontend Caching Explained

👉 Frontend System Design Essentials — Course: https://icodeit.thinkific.com/courses/frontend-system-design-essentials 👉 Frontend System Design Essentials — Book: https://leanpub.com/frontend-system-design-essentials/ Intro Frontend system design is not only about components and UI polish. Modern frontend apps are part of a distributed system: slow networks, failed requests, auth, permissions, and one constant problem — stale data. Caching sounds obvious (“don’t fetch the same data again”), but the real question is more subtle: When can you trust the cache? When should you refetch? And after a mutation, how do you keep the UI consistent? In this video we explore frontend caching from a system design perspective — not from one library’s API surface — using a product list example to reason about snapshots, trade-offs, cache layers, and mutation strategies. Final Takeaway Caching is choosing the right behavior for the situation. Start with the risk of being wrong, the cost of refetching, and what the user expects — then pick an approach that keeps the UI consistent after mutations. 00:00 Frontend caching: reuse vs refetch 01:41 About the channel 01:59 The frontend only has a snapshot 03:04 A simple implementation (component state) 04:18 Application-level cache (React Query) 06:12 Caching is a trade-off (staleTime) 07:30 staleTime live demo 09:10 Cache has layers 11:59 The hard part is mutation 12:48 Option 1 — invalidate and refetch 13:27 Option 2 — update cache from mutation result 14:49 Option 3 — optimistic update 15:35 A simple way to decide (4 questions) 18:47 Summary 📘 MY BOOKS & COURSES 👉 Frontend System Design Essentials (Course): https://icodeit.thinkific.com/courses/frontend-system-design-essentials 👉 Frontend System Design Essentials (Book): https://leanpub.com/frontend-system-design-essentials/ 👉 React Anti-Patterns (Amazon): https://www.amazon.com/dp/1805123971 👉 More Tutorials on Advanced Patterns: https://icodeit.com.au/tutorials/advanced-network-patterns-react 📩 STAY CONNECTED 🧠 Newsletter (system design & clean code): https://juntao.substack.com 🌐 Website & Blog: https://icodeit.com.au 🐦 Twitter / X: http://twitter.com/JuntaoQiu 📺 YouTube (subscribe): https://www.youtube.com/@icodeit.juntao 💬 Question for You When you build a data-driven UI, what do you optimize for first: fewer requests, fresher data, fewer loading spinners, or simpler cache logic? What caching mistake has bitten you the most: overly long staleness, invalidating too broadly, or inconsistent UI after mutation? Hashtags #frontend #systemdesign #caching #react #webdevelopment #javascript #frontendarchitecture #reactquery #frontenddevelopment