Design Interview Questions

Data structure design and API-oriented problems.

165 problems

#	Title	Difficulty	Topics
146	LRU Cache	Hard	design
173	Binary Search Tree Iterator	Medium	design
225	Implement Stack using Queues	Easy	design
284	Peeking Iterator	Medium	design
348	Design Tic-Tac-Toe	Medium	design
353	Design Snake Game	Medium	design
355	Design Twitter	Medium	design
359	Logger Rate Limiter	Easy	design
362	Design Hit Counter	Medium	design
379	Design Phone Directory	Medium	design
380	Insert Delete GetRandom O(1)	Hard	design
381	Insert Delete GetRandom O(1) - Duplicates allowed	Hard	design
432	All O\`one Data Structure	Hard	design
460	LFU Cache	Hard	design
489	Robot Room Cleaner	Hard	design
535	Encode and Decode TinyURL	Medium	design
588	Design In-Memory File System	Hard	design
604	Design Compressed String Iterator	Easy	design
622	Design Circular Queue	Medium	design
631	Design Excel Sum Formula	Hard	design
635	Design Log Storage System	Medium	design
641	Design Circular Deque	Medium	design
642	Design Search Autocomplete System	Hard	design
705	Design HashSet	Easy	design
706	Design HashMap	Easy	design
707	Design Linked List	Medium	design
715	Range Module	Hard	design
716	Max Stack	Easy	design
745	Prefix and Suffix Search	Hard	design
900	RLE Iterator	Medium	design
1146	Snapshot Array	Medium	design
1166	Design File System	Medium	design
1172	Dinner Plate Stacks	Hard	design
1206	Design Skiplist	Hard	design
1236	Web Crawler	Medium	design
1244	Design A Leaderboard	Medium	design
1268	Search Suggestions System	Medium	design
1286	Iterator for Combination	Medium	design
1348	Tweet Counts Per Frequency	Medium	design
1352	Product of the Last K Numbers	Medium	design
1357	Apply Discount Every n Orders	Medium	design
1381	Design a Stack With Increment Operation	Medium	design
1396	Design Underground System	Medium	design
1429	First Unique Number	Medium	design
1472	Design Browser History	Medium	design
1476	Subrectangle Queries	Medium	design
1483	Kth Ancestor of a Tree Node	Hard	design
1500	Design a File Sharing System	Medium	design
1570	Dot Product of Two Sparse Vectors	Medium	design
1586	Binary Search Tree Iterator II	Medium	design
1600	Throne Inheritance	Medium	design
1603	Design Parking System	Easy	design
1622	Fancy Sequence	Hard	design
1628	Design an Expression Tree With Evaluate Function	Medium	design
1656	Design an Ordered Stream	Easy	design
1670	Design Front Middle Back Queue	Medium	design
1756	Design Most Recently Used Queue	Medium	design
1797	Design Authentication Manager	Medium	design
1804	Implement Trie II (Prefix Tree)	Medium	design
1825	Finding MK Average	Hard	design
1845	Seat Reservation Manager	Medium	design
1865	Finding Pairs With a Certain Sum	Medium	design
1912	Design Movie Rental System	Hard	design
1993	Operations on Tree	Medium	design
2013	Detect Squares	Medium	design
2034	Stock Price Fluctuation	Medium	design
2043	Simple Bank System	Medium	design
2069	Walking Robot Simulation II	Medium	design
2080	Range Frequency Queries	Medium	design
2102	Sequentially Ordinal Rank Tracker	Hard	design
2166	Design Bitset	Medium	design
2227	Encrypt and Decrypt Strings	Hard	design
2241	Design an ATM Machine	Medium	design
2254	Design Video Sharing Platform	Hard	design
2276	Count Integers in Intervals	Hard	design
2286	Booking Concert Tickets in Groups	Hard	design
2296	Design a Text Editor	Hard	design
2336	Smallest Number in Infinite Set	Medium	design
2349	Design a Number Container System	Medium	design
2353	Design a Food Rating System	Medium	design
2408	Design SQL	Medium	design
2424	Longest Uploaded Prefix	Medium	design
2502	Design Memory Allocator	Medium	design
2526	Find Consecutive Integers from a Data Stream	Medium	design
2590	Design a Todo List	Medium	design
2618	Check if Object Instance of Class	Medium	design
2619	Array Prototype Last	Easy	design
2620	Counter	Easy	design
2621	Sleep	Easy	design
2622	Cache With Time Limit	Medium	design
2623	Memoize	Medium	design
2624	Snail traversal	Medium	design
2625	Flatten Deeply Nested Array	Medium	design
2626	Array Reduce Transformation	Easy	design
2627	Debounce	Medium	design
2628	JSON Deep Equal	Medium	design
2629	Function Composition	Easy	design
2630	Memoize II	Hard	design
2631	Group By	Medium	design
2632	Curry	Medium	design
2633	Convert Object to JSON String	Medium	design
2634	Filter Elements from Array	Easy	design
2635	Apply Transform Over Each Element in Array	Easy	design
2636	Promise Pool	Medium	design
2637	Promise Time Limit	Easy	design
2642	Design Graph With Shortest Path Calculator	Medium	design
2648	Generate Fibonacci Sequence	Easy	design
2649	Nested Array Generator	Medium	design
2650	Design Cancellable Function	Hard	design
2665	Counter II	Easy	design
2666	Allow One Function Call	Easy	design
2667	Create Hello World Function	Easy	design
2671	Frequency Tracker	Medium	design
2675	Array of Objects to Matrix	Medium	design
2676	Throttle	Medium	design
2677	Chunk Array	Easy	design
2690	Infinite Method Object	Medium	design
2691	Immutability Helper	Hard	design
2692	Make Object Immutable	Medium	design
2693	Call Function with Custom Context	Medium	design
2694	Event Emitter	Medium	design
2695	Array Wrapper	Easy	design
2700	Differences Between Two Objects	Medium	design
2703	Return Length of Arguments Passed	Easy	design
2704	To Be Or Not To Be	Easy	design
2705	Compact Object	Medium	design
2715	Execute Cancellable Function With Delay	Easy	design
2721	Execute Asynchronous Functions in Parallel	Medium	design
2722	Join Two Arrays by ID	Medium	design
2723	Add Two Promises	Easy	design
2724	Sort By	Easy	design
2725	Interval Cancellation	Easy	design
2726	Calculator with Method Chaining	Easy	design
2727	Is Object Empty	Easy	design
2754	Bind Function to Context	Medium	design
2755	Deep Merge of Two Objects	Medium	design
2756	Query Batching	Hard	design
2757	Generate Circular Array Values	Medium	design
2758	Next Day	Easy	design
2759	Convert JSON String to Object	Hard	design
2774	Array Upper Bound	Easy	design
2775	Undefined to Null	Medium	design
2776	Convert Callback Based Function to Promise Based Function	Medium	design
2777	Date Range Generator	Medium	design
2794	Create Object from Two Arrays	Easy	design
2795	Parallel Execution of Promises for Individual Results Retrieval	Medium	design
2796	Repeat String	Easy	design
2797	Partial Function with Placeholders	Medium	design
2803	Factorial Generator	Easy	design
2804	Array Prototype ForEach	Easy	design
2805	Custom Interval	Medium	design
2821	Delay the Resolution of Each Promise	Easy	design
2822	Inversion of Object	Easy	design
2823	Deep Object Filter	Medium	design
3242	Design Neighbor Sum Service	Easy	design
3369	Design an Array Statistics Tracker	Hard	design
3391	Design a 3D Binary Matrix with Efficient Layer Tracking	Medium	design
3408	Design Task Manager	Medium	design
3484	Design Spreadsheet	Medium	design
3508	Implement Router	Medium	design
3709	Design Exam Scores Tracker	Medium	design
3815	Design Auction System	Medium	design
3822	Design Order Management System	Medium	design
3829	Design Ride Sharing System	Medium	design
3885	Design Event Manager	Medium	design