System Design · Middle · Question 62 of 75

What does Background Sync help with in an offline-capable app?

✓Correct answer: Queuing failed requests and replaying them when connectivity returns, even if the page was closed
2Syncing CSS between tabs
3Speeding up downloads

Explanation

Browser support varies, so apps also keep their own queue (e.g. in IndexedDB) and retry on the online event.

Further reading

Test yourself

Take the System Design · Middle quiz: questions and options are shuffled, and you get a review of your mistakes at the end.