Interview Cache
Master your next technical interview with real questions from industry leaders.
Master your next technical interview with real questions from industry leaders.
127 problems across 4 categories
| Done | Title | Difficulty | Updated |
|---|---|---|---|
| Return Top K Open Businesses NewSoftware EngineerCoding | Hard | May 10, 2026 | |
| Implement Memory Allocation and In-Memory Records NewSoftware EngineerCoding | Medium | May 7, 2026 | |
| Design Chatbot Personalization Memory NewSoftware EngineerSystem Design | Medium | May 7, 2026 | |
| Sort Three Categories In Place Software EngineerCoding | Medium | Apr 18, 2026 | |
| Implement K-Means and Detect Divisible Subarrays Machine Learning EngineerCoding | Medium | Apr 18, 2026 | |
| Design A Scalable Web Crawler Software EngineerSystem Design | Medium | Apr 18, 2026 | |
| Design a Product Search System Machine Learning EngineerSystem Design | Medium | Apr 18, 2026 | |
| Retain Top K Elements Software EngineerCoding | Medium | Apr 17, 2026 | |
| Implement SFT Sample Packing Machine Learning EngineerCoding | Medium | Apr 13, 2026 | |
| Implement SQL Table and DNA Ordering Software EngineerCoding | Medium | Apr 10, 2026 | |
| Design User Re-engagement Notifications Software EngineerSystem Design | Medium | Apr 10, 2026 | |
| Solve power jumps and graph tour Software EngineerCoding | Hard | Apr 8, 2026 | |
| Implement concurrent structures and debug queue code Software EngineerCoding | Hard | Apr 7, 2026 | |
| Explain OOP design and API rollout Software EngineerCoding | Hard | Apr 7, 2026 | |
| Design a typeahead search service Software EngineerSystem Design | Hard | Apr 7, 2026 | |
| Design a Secure Copilot API Software EngineerSystem Design | Medium | Apr 6, 2026 | |
| Write an average-income function Data ScientistCoding | Easy | Apr 1, 2026 | |
| Query departments and top earners Data Scientist | Easy | Apr 1, 2026 | |
| Find Top K Largest Numbers Machine Learning EngineerCoding | Easy | Apr 1, 2026 | |
| Solve Throughput, Rate Limiting, and LFU Software EngineerCoding | Hard | Mar 20, 2026 | |
| Design a URL Shortener Software EngineerSystem Design | Hard | Mar 20, 2026 | |
| Return Top K Relevant Apps Software EngineerCoding | Medium | Mar 16, 2026 | |
| Design a RAG Ranking Pipeline Software EngineerSystem Design | Medium | Mar 16, 2026 | |
| Implement a Snapshot Set Iterator Software EngineerCoding | Medium | Mar 13, 2026 | |
| How do you choose a model? Machine Learning Engineer | Medium | Mar 10, 2026 | |
| Design quality checks for spreadsheet LLM data Machine Learning EngineerSystem Design | Medium | Mar 10, 2026 | |
| Reconstruct DNA from tagged fragments Software EngineerCoding | Medium | Mar 1, 2026 | |
| Implement a type-based mutex for tasks Software EngineerCoding | Medium | Mar 1, 2026 | |
| Find all balanced k in a permutation Software EngineerCoding | Hard | Mar 1, 2026 | |
| Design a ChatGPT-like serving system Software EngineerSystem Design | Medium | Mar 1, 2026 | |
| Compute discounted prices and full-price indices Software EngineerCoding | Hard | Mar 1, 2026 | |
| Answer common graph, grid, and array tasks Software EngineerCoding | Medium | Mar 1, 2026 | |
| Traverse an Org Chart by Level Data ScientistCoding | Medium | Feb 25, 2026 | |
| Explain SHAP in an ML System Data Scientist | Medium | Feb 25, 2026 | |
| Design Testing Without A/B Experiments Data ScientistProduct Sense | Medium | Feb 25, 2026 | |
| Choose Classification Metrics Under Asymmetric Costs Data Scientist | Medium | Feb 25, 2026 | |
| Implement cache and merge intervals Machine Learning EngineerCoding | Medium | Feb 23, 2026 | |
| Explain a project deeply Machine Learning EngineerCoding | Medium | Feb 23, 2026 | |
| Design chat and online chess Machine Learning EngineerSystem Design | Medium | Feb 23, 2026 | |
| Implement Matrix Move and Logger Software EngineerCoding | Medium | Feb 22, 2026 | |
| Implement Calendar, Tokenizer, and Meeting Optimizer Software EngineerCoding | Medium | Feb 22, 2026 | |
| Explain Python, Java, and Memory Management Software EngineerCoding | Medium | Feb 22, 2026 | |
| Design a URL Shortening Service Software EngineerSystem Design | Medium | Feb 22, 2026 | |
| Implement greedy decoding and beam search Software EngineerCoding | Medium | Feb 15, 2026 | |
| Stream output until stop token appears Software EngineerCoding | Medium | Feb 12, 2026 | |
| Remove duplicates in-place from unsorted array Software EngineerCoding | Medium | Feb 12, 2026 | |
| Implement interval room counter and token manager Software EngineerCoding | Easy | Feb 12, 2026 | |
| Implement four data-structure/string geometry tasks Software EngineerCoding | Medium | Feb 12, 2026 | |
| Find maximum collinear points Software EngineerCoding | Medium | Feb 12, 2026 | |
| Explain normalization, regularization, CTR, imbalance handling Software Engineer | Medium | Feb 12, 2026 | |
| Design a high-scale URL shortener Software EngineerSystem Design | Medium | Feb 12, 2026 | |
| Solve cache, grid path, and substring problems Software EngineerCoding | Hard | Feb 11, 2026 | |
| Implement idempotent request handling with idempotency keys Software EngineerCoding | Hard | Feb 11, 2026 | |
| Implement a sliding-window rate limiter allow() Software EngineerCoding | Hard | Feb 11, 2026 | |
| Implement a resumable data loader Machine Learning EngineerCoding | Medium | Feb 11, 2026 | |
| Find minimum moves to solve the 15-puzzle Software EngineerCoding | Hard | Feb 11, 2026 | |
| Find minimum cycle cost per node Software EngineerCoding | Hard | Feb 11, 2026 | |
| Explain how browser authentication works with JWTs Software EngineerCoding | Hard | Feb 11, 2026 | |
| Detect stop tokens during streaming inference Machine Learning EngineerCoding | Medium | Feb 11, 2026 | |
| Design a video VLM end-to-end Machine Learning EngineerSystem Design | Medium | Feb 11, 2026 | |
| Design a simple API rate limiter Software EngineerSystem Design | Hard | Feb 11, 2026 | |
| Design a job scheduler ETL pipeline system Software EngineerSystem Design | Hard | Feb 11, 2026 | |
| Decode a JWT string without libraries Software EngineerCoding | Hard | Feb 11, 2026 | |
| Compute product of array except self Software EngineerCoding | Hard | Feb 11, 2026 | |
| Clean OCR data and build an LLM dataset Machine Learning Engineer | Medium | Feb 11, 2026 | |
| Assemble async stream reads into objects Software EngineerCoding | Hard | Feb 11, 2026 | |
| Answer suffix maximum-frequency queries Software EngineerCoding | Hard | Feb 11, 2026 | |
| Use confusion matrix to choose model metric Data Scientist | Easy | Feb 9, 2026 | |
| Traverse org chart level by level Data ScientistCoding | Easy | Feb 9, 2026 | |
| Explain SHAP and build an ML project Data Scientist | Easy | Feb 9, 2026 | |
| Design evaluation when A/B test is impossible Data ScientistProduct Sense | Easy | Feb 9, 2026 | |
| Implement K-means clustering from scratch Machine Learning EngineerCoding | Medium | Feb 9, 2026 | |
| Find pairs with the minimum absolute difference Machine Learning EngineerCoding | Medium | Feb 9, 2026 | |
| Explain metrics, regularization, and ablation studies Machine Learning Engineer | Medium | Feb 9, 2026 | |
| Design a RAG system with agentic tools Machine Learning EngineerSystem Design | Medium | Feb 9, 2026 | |
| Compute precision/recall from a flaky top-k API Machine Learning EngineerCoding | Medium | Feb 9, 2026 | |
| Extract stream prefix before stop token Software EngineerCoding | Hard | Feb 1, 2026 | |
| Return a topological ordering of a graph Software EngineerCoding | Hard | Jan 22, 2026 | |
| Implement a rate limiter at scale Software EngineerCoding | Medium | Jan 22, 2026 | |
| Group GPUs by node and partition by links Software EngineerCoding | Hard | Jan 22, 2026 | |
| Design REST APIs for JSON file storage Software EngineerSystem Design | Medium | Jan 22, 2026 | |
| Design a resource change tracking database Software EngineerSystem Design | Medium | Jan 22, 2026 | |
| Design a live-stream comments system Software EngineerSystem Design | Hard | Jan 22, 2026 | |
| Explain KNN and how to tune it Data Scientist | Easy | Jan 17, 2026 | |
| Compute and plot a precision–recall curve Data Scientist | Easy | Jan 17, 2026 | |
| Design a Ticketmaster-like ticketing system Software EngineerSystem Design | Medium | Jan 9, 2026 | |
| Compute distance of each node to a cycle Software EngineerCoding | Medium | Jan 9, 2026 | |
| Check palindrome number and next palindrome Software EngineerCoding | Medium | Jan 9, 2026 | |
| Validate a JSON-like string Software EngineerCoding | Medium | Jan 6, 2026 | |
| Rotate a 3×3 digit grid by 180° Software EngineerCoding | Medium | Jan 6, 2026 | |
| Optimize vector semantic search for an assistant Machine Learning EngineerSystem Design | Medium | Jan 6, 2026 | |
| Infer user intent from typing in real time Machine Learning EngineerSystem Design | Medium | Jan 6, 2026 | |
| Design email ranking and summarization in Outlook Machine Learning EngineerSystem Design | Medium | Jan 6, 2026 | |
| Design a RAG-based assistant service Machine Learning EngineerSystem Design | Medium | Jan 6, 2026 | |
| Compare preference alignment methods for LLMs Machine Learning Engineer | Medium | Jan 6, 2026 | |
| Calibrate LLM output to match Word formatting Machine Learning EngineerSystem Design | Medium | Jan 6, 2026 | |
| Design an online ticket booking system Software EngineerSystem Design | Medium | Jan 3, 2026 | |
| Compute shortest path in cyclic graph Software EngineerCoding | Medium | Jan 3, 2026 | |
| Check palindrome and find next larger palindrome Software EngineerCoding | Medium | Jan 3, 2026 | |
| Explain Transformers and deploy an LLM safely Machine Learning EngineerSystem Design | Easy | Dec 27, 2025 | |
| Explain bias-variance and evaluate a classifier Machine Learning Engineer | Easy | Dec 27, 2025 | |
| Solve binary-tree reverse printing and LPS Software EngineerCoding | Easy | Dec 24, 2025 | |
| Design a cloud console main page Software EngineerSystem Design | Medium | Dec 15, 2025 | |
| Assemble DNA payload strings from tagged fragments Software EngineerCoding | Medium | Dec 15, 2025 | |
| Solve four classic algorithm problems Software EngineerCoding | Easy | Nov 30, 2025 | |
| Implement a calendar with non-overlapping bookings Software EngineerCoding | Medium | Nov 25, 2025 | |
| Find longest substring without repeating characters Software EngineerCoding | Medium | Nov 25, 2025 | |
| Merge overlapping intervals Software EngineerCoding | Medium | Nov 19, 2025 | |
| Find lowest common ancestor in tree Software EngineerCoding | Medium | Nov 19, 2025 | |
| Design local sports team recommendation system Software EngineerSystem Design | Medium | Nov 19, 2025 | |
| Find max consecutive elements with sum below target Software EngineerCoding | Medium | Nov 17, 2025 | |
| Count integer pairs satisfying 1/x + 1/y = 1/N Software EngineerCoding | Medium | Nov 17, 2025 | |
| Find shortest substring with n unique letters Software EngineerCoding | Medium | Nov 3, 2025 | |
| Design top-K frequency store for varying workloads Software EngineerCoding | Medium | Nov 3, 2025 | |
| Solve three scheduling and array problems Software EngineerCoding | Medium | Oct 28, 2025 | |
| Reverse linked list in fixed-size groups Software EngineerCoding | Medium | Oct 28, 2025 | |
| Merge multiple sorted arrays using min-heap Software EngineerCoding | Medium | Oct 28, 2025 | |
| Discuss mutexes, memory alignment, polymorphism, idempotency Software EngineerCoding | Medium | Oct 28, 2025 | |
| Implement a Tic-Tac-Toe game class Software EngineerCoding | Medium | Oct 14, 2025 | |
| Design cache with least-recently-used eviction Software EngineerCoding | Medium | Oct 14, 2025 | |
| Build a time-based key-value store Software EngineerCoding | Medium | Oct 14, 2025 | |
| Solve two-pointer, sliding-window, and string tasks Data ScientistCoding | Medium | Oct 13, 2025 | |
| Compute sample size and analyze A/B results Data Scientist | Medium | Oct 13, 2025 | |
| Compare CNN/RNN/LSTM and implement K-means Data Scientist | Hard | Oct 13, 2025 | |
| Implement lower_bound on unknown-size sorted array Data ScientistCoding | Hard | Oct 13, 2025 | |
| Test classifier difference with McNemar's test Data Scientist | Medium | Oct 13, 2025 | |
| Implement robust k-means from scratch Data Scientist | Hard | Oct 13, 2025 |