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Amazon interview notes, page 51 of 159

FAANG / Big Tech

Most of these Amazon write-ups come from Software Engineers (1,092), then Data Scientists (182) and Product Managers (165). The most reported rounds are the technical phone screen (618), the behavioral / leadership round (309), the online assessment (228) and the system design round (159).

1581 interview notes · updated Oct 2026

Amazon·Machine Learning Engineer·Technical Phone Screen

May 2026
Amazon ML Engineer technical screen, one coding problem the whole time. The question was a bit of a curveball if you haven't seen it before, but manageable once you figure out the angle they're going for.
  • Given two 32-bit signed integers, divide the dividend by the divisor and return the integer quotient without using multiplication, division, or modulo operators. Handle overflow and aim for better than linear time complexity.

“My first instinct was just repeated subtraction and I actually started explaining that before catching myself.”

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Amazon·Software Engineer·Online Assessment (OA)

May 2026
Amazon SWE online assessment, two algorithmic problems. Nothing too wild but the second one had me second-guessing my approach for longer than I'd like to admit.
  • Given a string and an integer k, count the number of valid split indices where partitioning the string into a non-empty prefix and non-empty suffix results in strictly more than k distinct characters appearing in both parts simultaneously.
  • Given an array of item prices, form packages where each package holds at most two items and all packages share the same total cost S. Items can't be reused. Single-item packages are valid only if the item's cost equals S. Pick S to maximize the number of packages and return that count.

“Prefix/suffix character overlap counting.”

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Amazon·Software Engineer·Technical Phone Screen

May 2026
Amazon SWE coding round, one meaty DP problem about resolving unknown characters in a string to minimize subsequence costs. Not a typical easy/medium grind question, more like the kind of thing that exposes whether you actually understand DP or just memorized patterns.
  • You're given a string of '0', '1', and '!' characters. Each '!' can be replaced with either '0' or '1'. You're also given two costs x and y. Every '01' subsequence in the final string costs x, every '10' subsequence costs y. Find the assignment of '!' characters that minimizes total cost.

“My first instinct was brute force since the number of '!' could be small, and I think it was actually the right move to mention that O(2^k) baseline before jumping in.”

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Amazon·Software Engineer·Online Assessment (OA)

May 2026
Amazon SWE coding round, one problem about building an inverted index to support sentence search with add, delete, and query operations. Pretty standard data structures problem but the deletion part tripped me up a bit.
  • Design a sentence search system that maps words to sentence IDs. Support adding a sentence by ID, deleting a sentence by ID, and querying all current sentence IDs that contain a given word (returned sorted).

“My first instinct was just a plain hashmap from word to a list of IDs, which works fine for ADD and QUERY.”

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Amazon·Machine Learning Engineer·Technical Phone Screen

May 2026
Amazon ML engineer interview, technical phone screen focused on deep learning fundamentals. The dropout question sounds basic until they start asking about the math behind it.
  • Implement dropout in code, and explain the difference between how it behaves during training versus inference, including why you divide activations by the keep-probability during training (inverted dropout). Follow-up: what happens if you leave dropout on at test time?

“I wrote the code fine but fumbled the explanation of the scaling factor.”

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Amazon·Software Engineer·Onsite - System Design / Architecture

May 2026
Amazon system design round for a software engineer role. The whole session was basically one giant question about traffic light control systems, then some follow-ups about testing and optimization. Dense and exhausting.
  • Design a traffic light control system for a multi-road intersection. You need to define your goals and assumptions upfront, cover the core components, data model, APIs, state machine for signal phases, timing logic, cross-approach coordination, and how you handle peak vs off-peak patterns.
  • How would you handle safety concerns like conflict avoidance and all-red intervals, concurrency issues, preemption for emergency vehicles or transit priority, failure detection, and safe fallback modes?
  • How would you approach monitoring, observability, deployment, and scaling this system to a citywide network?
  • If you had more time, what optimizations would you add to this system?
  • How would you design comprehensive unit tests and simulations for this system, including deterministic time control and edge cases?

“This was the main question and it ate up most of the session.”

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Amazon·Software Engineer·Technical Phone Screen

May 2026
Amazon SWE interview with a system design coding problem around a music player. The problem had more moving parts than it looked at first glance, and the follow-ups pushed pretty hard on scalability and concurrency.
  • Design and implement a music player that accepts song lists from new users and plays songs in descending frequency order without repeating a song within the same cycle. You need to support two operations: adding a user's songs (which updates global play counts) and getting the next song to play.
  • How would you make this music player implementation thread-safe?
  • How would you redesign this if the song catalog was too large to fit on a single machine?
  • How would you support deleting a song or decreasing its frequency?

“The cycle reset logic is what tripped me up.”

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Amazon·Software Engineer·Online Assessment (OA)

May 2026
Amazon coding question, greedy/DP flavored, the kind that looks like a simple array problem until you actually try to implement it.
  • You have n cities in a row, each with a population value. Some cities start with a safety unit, some don't. Each safety unit can either stay in place or move one step left, and can only be moved once. A city is considered protected if it ends up with at least one safety unit. Find the optimal set of moves to maximize the total population of protected cities.

“Spent the first few minutes just re-reading the constraints because I kept second-guessing whether units could move right too.”

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Amazon·Software Engineer·Online Assessment (OA)

May 2026
Amazon SWE coding question about grouping students by score balance. Pretty standard algorithmic problem but the balancing constraint is where things get interesting.
  • Given an array of student scores and an integer n, divide the students into n groups such that the score sums across groups are as balanced as possible. Return the sum of scores for each group.

“The example they give is clean: [10, 20, 30, 40] into 2 groups gives [50, 50].”

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Amazon·Software Engineer·Technical Phone Screen

May 2026
Amazon SWE coding round, one question, classic graph problem. Nothing too wild but apparently a lot of intern candidates fumble this topic so worth knowing cold.
  • Given a list of nodes and edges, find the number of connected components in an undirected graph.

“Union-Find is the move here.”

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