Snap interview notes, page 13 of 22

Large Enterprises

Most of these Snap write-ups come from Software Engineers (117), then Machine Learning Engineers (65) and Data Scientists (18). The most reported rounds are the technical phone screen (149), the system design round (45), the behavioral / leadership round (11) and the product sense round (8).

216 interview notes · updated Jul 2026

Snap·Software Engineer·Onsite - System Design / Architecture

May 2026

Snapchat system design round focused entirely on the backend feed service for a short-video product, basically the thing that powers swipe-up/swipe-down. Pretty scoped question on paper but it sprawls fast once you get into ranking, caching, and abuse controls.

Design the backend feed service for a short-video product: the client requests an ordered list of video IDs, supports endless scrolling with low latency, personalized ranking with a non-personalized fallback, and avoids showing duplicate content while supporting next/previous navigation.

“I started with the API contract and worked inward, which felt right.”

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Snap·Machine Learning Engineer·Onsite - Product Sense / Strategy

May 2026

Product sense round for an MLE role at Snapchat. The question was one of those open-ended product teardowns that sounds easy until you're actually in it trying to balance user empathy with business logic on the fly.

Pick a product you use regularly. Walk through what makes it work, who uses it, what problems it solves for users and the business, then propose specific improvements with your reasoning, how you'd prioritize them, how you'd measure success, and what trade-offs you'd be making.

“I picked a product I genuinely use a lot, which I thought would help, but I spent too long on the 'what makes it work' section and had to rush through the improvements part.”

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Snap·Software Engineer·Technical Phone Screen

May 2026

Security engineer interview at Snap with a question that puts you in the attacker's seat. Pretty interesting angle compared to the usual defensive posture questions I've seen elsewhere.

You've compromised a certificate authority and stolen its private key. As an attacker, what do you do with it?

“This one flipped the usual framing and I liked it more than I expected.”

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Snap·Software Engineer·Online Assessment (OA)

May 2026

Snapchat iOS interview on HackerRank, pure Swift and GCD concurrency stuff, no UI questions at all. The interviewer literally writes code in front of you and asks what it prints and where it runs. Niche format but kind of refreshing compared to the usual leetcode grind.

Given this Swift snippet using a serial DispatchQueue with one async block and one sync block followed by a print on the calling thread, predict the output and identify which thread each print statement runs on.

“The async block goes first so print(1) gets dispatched and starts running on the queue's worker thread while the main thread moves on.”

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Snap·Machine Learning Engineer·Technical Phone Screen

May 2026

Snapchat ML engineer interview that came down to a classic k-sum coding problem. Nothing too exotic, but the edge cases around duplicates are where things get slippery.

Given an integer array and a target value, find all unique quadruplets of elements that sum to the target.

“The core idea isn't hard once you've done 3Sum before.”

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Snap·Software Engineer·Technical Phone Screen

May 2026

Snapchat software engineer interview with a graph/Union-Find problem. Pretty standard algorithmic round, one question, and the whole thing hinged on whether you could spot the connected components insight fast enough.

Given n stones placed on a 2D grid, a stone can be removed if it shares a row or column with at least one other remaining stone. What is the maximum number of stones you can remove?

“The brute force instinct here is a trap you have to talk yourself out of.”

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Snap·Machine Learning Engineer·Technical Phone Screen

May 2026

Snap ML engineer interview, got a system design style question about handling long inputs in generative models. Pretty technical, felt like they wanted to see if you'd actually thought about this in practice rather than just reciting textbook answers.

Your generative model needs to handle inputs that are longer than what the context window supports. How do you deal with that?

“I went straight to chunking and retrieval augmentation, which felt safe but maybe too surface level.”

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Snap·Machine Learning Engineer·Technical Phone Screen

Jun 2026

Snapchat ML engineer interview that was heavier on algorithms than I expected. The grid traversal problem was manageable but the follow-up with two users caught me off guard and I had to think out loud for a while before landing on something reasonable.

You have an m×n grid where walls (1), empty cells (0), and meeting rooms (2) are marked. Given a starting position, find the coordinates of the nearest reachable meeting room using unit-cost moves in four directions. Return [-1, -1] if none are reachable. Walk through your algorithm and its time and space complexity.
Follow-up: given two users starting at different positions, find the meeting room that minimizes the combined shortest-path distance for both, considering only rooms both users can actually reach. Return the room coordinates and the minimum total distance.

“BFS was the obvious call here and I got there pretty fast.”

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Snap·Machine Learning Engineer·Technical Phone Screen

Jun 2026

Snapchat ML engineer interview with a binary search coding round. Pretty focused on correctness and being able to talk through your reasoning, not just getting to an answer.

Implement binary search or a variant (like lower_bound, upper_bound, or find first/last occurrence), and walk through your loop invariants and how you handle edge cases such as an empty array, a single element, a target outside the range, and duplicates.

“I went with lower_bound first since it felt cleaner to reason about.”

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Snap·Software Engineer·Technical Phone Screen

Jun 2026

Snapchat software engineer interview with a grid-based algorithm problem. Pretty standard coding round but the problem had a twist that tripped me up a bit.

Given a 2D grid of land and water cells, find the maximum perimeter across all islands, where an island is a group of land cells connected horizontally or vertically. Return 0 if there's no land.

“My first instinct was to just count edges per cell and sum them up, which is the right direction, but I kept second-guessing myself on whether to use BFS or DFS to group cells per island.”

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