iOS performance interview questions
Profiling with Instruments, smooth scrolling, rendering, launch time, app size and measuring before fixing.
– interview-ready · 10 questions in this topic
– of 10 tried
Saved on this device. Interview-ready means you got it right on two different days. Guesses and hints count for less.
Questions
- Profiling an iOS appPick the fix
- Dropped frames and hitchesPredict
- Smooth scrolling in listsPick the fix
- Offscreen renderingPick the fix
- Lazy loadingPick the fix
- Reducing app sizePick the fix
- Fixing a launch time regressionOrder the steps
- Measuring a slow screen without guessingPick the fix
- A 50,000-item list that stutters on updatesPick the fix
- From a tap to a pixel on screenOrder the steps
Practise this topic
Flashcards · 13
Flip, then say if you knew it. Needs JavaScript; every answer is also on its question page.
Quick quiz · 10 questions
One exercise per question, checked as you go. Needs JavaScript.
Mock interview · 2 sets
Timed, out loud, then tick what you covered. Needs JavaScript.
Quick facts
Recall the answer first, then tap Show to check.
MetricKit
Delivers daily metrics and diagnostics (hangs, crashes, launch time, battery) from real users' devices.
App Thinning
The App Store delivers only the device's variant of assets (slicing) and can host on-demand resources.
FormatStyle
date.formatted(.dateTime.day().month())caches formatters for you, unlike creating DateFormatters per call.
Printable cheat sheet · Review your weak spots in this topic