Interview Notes
Questions, approaches and lessons from every OA and VO.
Amazon New Grad Four-Round VO: What Changed This Year + Three Business-Scenario Coding Questions + Bar Raiser Deep Dive
Amazon new grad four-round VO recap: this year's shift to team-based hiring, four rounds, a stronger Bar Raiser and AI questions; three business-framed coding problems — Promotion Eligibility, Vendor Contract Registry, Return Requests — with reference implementations, and key behavioral deep-dive points.
DoorDash's Most Frequent System Design Question: Review & Reward System (Vote Aggregation + Rewards Triggered Exactly Once)
Breaking down DoorDash's frequent system design question: a food-delivery review and reward system — caching for read-heavy reviews, vote deduplication with async aggregation (Kafka + materialized views), exactly-once reward jobs (at-least-once delivery + an idempotent state machine), and failure handling.
Google 2027 SWE Intern VO, Fresh Recap: HashMap + Sliding Window and Graph BFS
Google 2027 SWE Intern VO recap, two technical rounds: round one was HashMap + sliding window, optimized from brute force to O(n); round two was graph BFS with follow-ups on huge graphs, cycles, returning the path and saving space, plus a recommended answer flow.
Google Summer Intern | SDE Summer Internship | Real Google Interview Questions
Real questions from Google's SDE summer internship VO: longest substring without repeating characters (sliding window + hash map, with a follow-up returning the substring itself) and binary tree right side view (BFS / DFS, with a follow-up on each level's outermost nodes), plus the process and Python reference code.
Microsoft 2026 Intern Interview | Microsoft Internship | Real Questions
Microsoft 2026 Intern two-round interview recap: behavioral questions focus on collaboration and ownership; coding is driven by verbal requirements with constraints added along the way — round one a file path manager (tree + HashMap), round two a message subscription system (bidirectional maps), with reference implementations.
Microsoft SDE Intern Interview | Two-Round Microsoft SDE Recap | Microsoft Internship
Microsoft SDE Intern two-round recap: an Azure-themed key-value store (put / get / getWithPrefix, evolving from a HashMap to a Trie) and a Bing / Teams-themed rate limiter (sliding window and token bucket), with reference implementations and a scalability discussion.
Stripe SDE VO | How the Integration Round Works
A full breakdown of Stripe's integration interview: clone a repo from GitHub, read the problem from an issue; the frequent Bikemap question covers GeoJSON parsing, POSTing for a map image, drawing with staticmap and finding the nearest landmark, with a Python reference implementation and prep tips.
TikTok Data Engineer Interview | TikTok New Grad, Full Process
TikTok Data Engineer new grad interview, start to finish: a resume deep dive (Flink checkpoints, state growth, back pressure), two SQL questions (daily active user growth, top creators by engagement and optimizing big-table joins) and a Python log-pattern question, with SQL and Python reference implementations.
TikTok 2027 CodeSignal OA: Even Digit Count, Cyclic-Shift Difference Sums, Bouncing Diagonals, Most Points in a Range
TikTok 2027 CodeSignal OA from the new question bank, four approaches: check whether a number has an even digit count, sums of absolute differences under cyclic shifts, simulating a bouncing diagonal, and choosing a center that covers the most points within 2*lim (sliding window).
TikTok Data Science OA, 4 Questions Done in 28 Minutes: Metrics, Table Merges, Feature Preprocessing, Random Forest Threshold Tuning
TikTok DS OA recap: computing average rating, second-language share and success rate with Pandas; merging multiple tables; train-set-based imputation, categorical encoding and standardization (avoiding data leakage); and tuning a random forest's threshold on a validation set to balance precision and recall.
TikTok OA, All 4 Passed: Min in a Range, Sorting by Vowel Gap, Bouncing Diagonals, Subarrays with at Least k Fruit Pairs
TikTok OA recap with all four passed: the minimum inside an open range, sorting words by the vowel/consonant gap, sorting by bouncing-diagonal weight, and counting subarrays with at least k pairs of the same fruit using a sliding window, with Python reference code.
Four Classic TikTok OA Questions: Adjacent Character Changes, Closest Earlier Timestamp, Placing Shapes, Fewest Operations to an Arithmetic Sequence
TikTok OA, four approaches: count adjacent differing characters ignoring case, find the closest timestamp before the current time, simulate placing shapes A–E in row-major order, and the fewest +1 operations to turn an array into an arithmetic sequence with difference ±1.
Amazon China SDE 27NG Four-Round VO: GenAI Behavioral + Topological Sort + Minimum Size Subarray + Binary Search
Amazon China SDE 2027 new grad four-round VO recap: GenAI-themed behavioral questions (LPs and STAR tips), topological sort for product release order, minimum size subarray sum >= target, and a lower-bound binary search for inventory thresholds, with clarifying questions and follow-ups.
Amazon New Grad Interview Question: TaskScheduler, Fully Analyzed (Topological Sort)
Breaking down Amazon's frequent new-grad OOD question TaskScheduler: model task dependencies as a DAG, use Kahn's topological sort (in-degree + BFS) for the execution order, detect dependency cycles and raise an exception, with a runnable reference implementation.
Amazon SWE 26NG Four Rounds: Dijkstra Delivery Routes + Sliding Window + Top K Orders + Bar Raiser
Amazon SWE 2026 new grad four-round recap: fastest delivery time across a warehouse network with Dijkstra, longest subarray with order total under a threshold (sliding window), real-time top K orders (size-K min-heap), plus project deep dives and Bar Raiser leadership principle follow-ups.
Amazon SWE Four-Round VO (Passed): Bracket Nesting Depth + Group Anagrams + Vending Machine OOD
Amazon SWE four-round VO that I passed: detailed behavioral follow-ups, maximum bracket nesting depth, grouping anagrams without sorting (count array as the key), a vending machine OOD with a Coin base class, and tips for behavioral answers that map to the Leadership Principles.
Amazon VO: Behavioral Deep Dive + Document Processing Under Limited Capacity + Splitting Alexa Conversations into Sessions
Amazon VO recap: behavioral questions on scope creep, trade-offs under tight deadlines and asking for resources; a system design for maximizing useful output from massive document data under a QPS limit; and splitting Alexa conversations into sessions by 60-second gaps, with an out-of-order insertion follow-up.
Amazon VO, Two Coding Rounds: Meeting Rooms + Arithmetic Expression Evaluation (Two Stacks)
Amazon VO two coding rounds: minimum number of meeting rooms (sort + min-heap), and evaluating arithmetic expressions with + - * / and parentheses using two stacks for precedence and nesting, with division truncating toward zero — plus a reference implementation.
Apple SWE VO, Four Rounds: Debugging a Swift Class Hierarchy + Focus Mode Schedule API + Telemetry Monitoring Design
Apple SWE four-round VO recap: reading a Swift base class to find inheritance flaws, a non-overlapping device focus-mode scheduling API, designing a telemetry monitoring system for a huge fleet of devices, and a hiring-manager project deep dive, with interview tips and a reference implementation.
Google 2027 SDE Intern (Passed): Undirected Unweighted Graph — Fewest Edges for Alice and Bob to Reach the Destination
A Google 2027 Summer Intern VO question: in an undirected unweighted graph, Alice starts at A and Bob at B, both heading to D; minimize the size of the union of edges on their two paths. Three BFS runs plus enumerating the meeting point, O(V+E).
Google SDE 2027 Intern: Subarray Sum Modulo Equals k + Three Follow-ups
Google SDE 2027 Intern interview: decide whether some contiguous subarray's sum modulo 700001 equals k, using prefix-sum remainders and a hash set; follow-ups cover negative numbers, the shortest such subarray, and streaming a huge array.
Google 2027 Summer Intern VO, Two Pure Coding Rounds: Islands in a Tree + Subarray Sum Modulo
Google 2027 Summer Intern VO recap: two 45-minute pure algorithm rounds, no behavioral. Round 1 counts islands of connected 1s in a binary tree (DFS / iterative); round 2 uses prefix-sum congruence to decide whether a subarray sum mod 6000009 equals k.
Google Intern VO, Two Rounds: Meeting Rooms II + Convert a BST to a Sorted Circular Doubly Linked List
Google Intern VO two-round recap: round one was Meeting Rooms II (sort + min-heap); round two had behavioral questions (recovering from a mistake, taking ownership) and converting a BST in place into a sorted circular doubly linked list via in-order traversal.
Google SDE VO: Passed Both Rounds (Behavioral + Locker System)
Google SDE VO two-round recap: behavioral questions on team disagreements, cross-team collaboration and performance bottlenecks; coding a locker system with a min-heap and a hash map for storing and retrieving, returning the most recently assigned locker number.
Google SDE VO Round 1: Minimum Cars for Rental Records + Assignment (Sort + Min-Heap)
Google SDE VO round one recap: after a quick project chat, a car rental scheduling problem — given unsorted pickup/return records, return the minimum number of cars and which car serves each record, using sorting and a greedy min-heap.
Google Interview: YouTube View Statistics (Prefix Sums) + Newly Painted Area per Day
Google two coding rounds: YouTube view range queries and counting hot windows (prefix sums + two pointers), and the newly painted area per day (merging intervals in a sorted set), with follow-up ideas and code.
Meta E4 Phone Screen + VO (Passed): Max Parenthesis Depth, Max Leaf-to-Leaf Path Sum, Design Dropbox
Meta E4 interview: phone screen with LC 125 and LC 938; final round with two coding interviews (Kth Largest, LC 827, max parenthesis depth, max leaf-to-leaf path sum), a Dropbox system design and behavioral — on my third attempt I finally reached team matching.
Stripe VO (2026–2027): Payment Transaction Risk Linkage System in 3 Progressive Parts
Stripe VO coding recap: finding risk-linked payment transactions — Part 1 attribute matching, Part 2 configurable weighted scoring, Part 3 second-degree indirect links with BFS — with a layered code design and what the interviewer focused on.
TikTok 2027 Intern OA (10/2): Robot Position, KMP Pattern Matching, Bouncing Diagonals, Max Profit After a Strategy Change
TikTok 2027 Intern OA, all four questions explained: the robot's final L/R direction, counting a pattern in a comparison array (KMP), sorting the first column by bouncing-diagonal weight, and maximizing profit by modifying a length-k window of a trading strategy (prefix sums).
TikTok MLE 2027 New Grad OA, All Correct: 6 Multiple Choice + 1 Fill-in + 3 Coding
TikTok MLE 2027 new grad OA, all correct: 6 multiple-choice questions, 1 fill-in-the-blank and 3 coding problems. Scored out of 600; currently anything above 400 gets a VO, and the earlier you take it the lower the bar.
Two Sigma OA, 3 Questions Passed: 2D Data Points + Pandas Filtering + Asset Returns via Linear Regression
Two Sigma OA recap: 3 questions in 100 minutes covering 2D data point processing, Pandas data filtering, and computing asset returns with linear regression coefficients (beta / alpha), with key concepts and Python reference code.
Amazon SDE 26NG Four-Round VO (9/4, Offer): Three Behavioral Rounds + Path Sum II
Amazon SDE 2026 new grad four-round VO with an offer: three behavioral rounds digging into technical disagreements, a feature with poor user experience and a production incident, and a single coding round on binary tree Path Sum II (DFS + backtracking), with a follow-up on negative values.
Google SDE VO (September), Two Rounds: Kth Largest in a Stream + Top K from Massive Data + Longest Consecutive Sequence
Google SDE VO two-round recap: round one had 3 behavioral questions plus kth largest element in a stream (size-K min-heap); round two had the K closest stars from massive data (size-K max-heap, O(N log K)) and longest consecutive sequence (hash set, O(n)).
TikTok OA (8/13), Same Questions Again: 4 CodeSignal Problems in 70 Minutes, All Passed
TikTok OA on CodeSignal: 4 coding questions in 70 minutes, all passed in half an hour. Exactly two equal among three consecutive numbers, remaining segments after destroying houses (reverse restore), a+b pair counting with updates (frequency maps), and sorting matrix borders layer by layer.
Google SDE VO (8/5): Pure Behavioral + Car Rental Interval Scheduling — Passed
Google SDE VO two-round recap: round one was pure behavioral (biggest weakness, why you're leaving, five-year plan); round two was car rental interval scheduling using a sweep line plus an idle-car pool to find the minimum number of cars and an assignment.
Anthropic Four-Round VO (Offer, August): Call-Stack Profiler + Streaming LLM Inference API + Lock-Free Priority Queue
How I approached Anthropic's four VO rounds and got an offer: a call-stack profiler state machine, streaming LLM inference API system design (multi-tenancy, rate limiting, KV cache), a lock-free concurrent priority queue, and an AI-safety values behavioral round.
Walmart Experienced-Hire Interview (August): Sliding Window Maximum with a Priority Queue + Optimization
Walmart experienced SDE interview: a verbally described sliding window maximum problem. Priority queue solution in O(n log n), then the follow-up optimization to a monotonic queue in O(n), with time and space complexity analysis.
Meta SDE Interview: Rack Allocation + Restaurant Seating + Playlist Shuffle + Kafka Deep Dive
Meta SDE four-round recap: GenAI development follow-ups, rack allocation with a sorted ceiling lookup, restaurant seating with tables indexed by size plus a FIFO queue, a Kafka hot-partition behavioral deep dive and a shuffle algorithm, plus coding and system design prep tips.
Amazon 26NG OOD Interview: Design a Multi-Elevator Dispatch System
Amazon 2026 new grad OOD round: behavioral questions on urgent requests and task allocation; design a multi-elevator system with request queues, up/down scheduling, overload checks and a pluggable dispatch strategy, with follow-ups on peak hours, VIP priority and fire mode.
Amazon SDE VO (4/14): Timeline + Two-Round Recap (Locker & Meeting Rooms)
Amazon SDE VO two-round recap: hiring-manager round with 3 behavioral questions (conflict, high-pressure delivery, GenAI productivity) plus Locker & Package design; second round with a deep cross-team collaboration dive and Meeting Rooms I/II (min-heap and sweep line).
Amazon Intern VO (Offer!): N-ary Trees + Course Schedule Variant + Full Timeline
Amazon SDE Intern VO with an offer: behavioral questions on supporting peers, challenges and AI-assisted coding; three coding questions on N-ary tree subnodes, max depth and an LC 210 variant with cycle detection, plus the full timeline from application to offer.