Machine Coding Round

0 / 61 completed

Real Flutter live-coding tasks asked in interviews — fix bugs, predict output, review code, build UIs against the clock.

Done	Problem	Frequency	Note	Revision	Difficulty
	Restaurant of the Week spotlight screenNew				Medium
	Sync button silently does nothing on failure				Medium
	An async* generator with no listener: does any code inside it run?				Easy
	async error routing: does a sync throw inside an async function become a Future error?				Hard
	Settings toggle saves twice per tap				Medium
	A broadcast stream with a late subscriber: does it receive earlier events?				Easy
	Completer + spin loop: does while (!done) polling ever unblock?				Hard
	Search input that keeps clearing itself				Easy
	Submit button crashes after "Are you sure?"				Medium
	Custom == and hashCode: does identical() still detect separate objects?				Medium
	Default equality: do two objects with the same field values compare equal?				Easy
	Event loop basics: in what order do sync, Future, and microtask run?				Easy
	Event loop: how do Futures, .then() chains, and microtasks interleave?				Medium
	Flutter tap handler: predict the order of all eight async scheduling calls				Hard
	final vs const lists: which .add() calls succeed and which throw?				Medium
	Future.wait: does it wait for all futures or abort on the first error?				Medium
	FutureBuilder: how many times does the builder function run for one future?				Medium
	Profile screen flashes a spinner				Medium
	HashSet with custom ==: does adding two equal objects give one entry or two?				Hard
	Leaderboard rendering				Medium
	Photo gallery OOM crashes				Medium
	Signup form hides the field you're typing in				Easy
	A late field read before assignment: does it compile, return null, or crash?				Easy
	Auth service — works locally, crashes in CI				Medium
	const list canonicalization: when does identical() return true for two lists?				Medium
	Assigning one list to another variable: does mutating b also change a?				Easy
	Notifications feed PR				Easy
	Promo banner widget				Medium
	A microtask that keeps scheduling another microtask: what happens to the app?				Hard
	Profile screen throws after quick back-tap				Easy
	?? vs ??=: which one actually updates the variable, and which only reads?				Easy
	Animated profile cards				Hard
	Stats dashboard with tap counter				Medium
	Pass by value: does incrementing an int parameter change the caller's variable?				Easy
	Profile name overflows on long names				Easy
	Performance PR for the activity feed				Medium
	??= chaining: once a variable is set, do later ??= assignments overwrite it?				Easy
	Add-to-cart items don't refresh after tapping add				Easy
	Log stream throws "already been listened to" at runtime				Easy
	Synchronous sleep: does it delay a Timer that was already scheduled?				Medium
	VIP-highlighted user list				Medium
	Live prices screen crashes after you navigate back				Easy
	Items list flashes a spinner when the keyboard opens				Medium
	Counter keeps ticking after leaving the screen				Easy
	Auth refresh that logs users out				Hard
	Two Completers each awaiting the other: what does this program print?				Hard
	One-on-one chat screen				Medium
	Drawings home screen				Easy
	Login with persistent session				Medium
	Movie watchlist app				Medium
	Offline-first todo app				Hard
	Phone number verification flow				Medium
	Render-tree visibility probe via HTTP				Hard
	Searchable user directory				Easy
	Cart screen				Medium
	Discovery card swipe				Hard
	Weight tracking app				Hard
	Feed crashes with a layout error on open				Medium
	Edit-profile screen				Easy
	yield* error handling: does a try/catch around yield* catch the inner stream's errors?				Medium
	yield vs yield: in what order do two composed async generators emit values?				Easy