← Back to Directory

ByteDance interview notes, page 3 of 29

FAANG / Big Tech

Most of these ByteDance write-ups come from Software Engineers (194), then Machine Learning Engineers (45) and Data Scientists (17). The most reported rounds are the technical phone screen (227), the system design round (28), the behavioral / leadership round (16) and the onsite coding round (9).

289 interview notes · updated Sep 2026

ByteDance·Software Engineer·Onsite - Behavioral / Leadership

Apr 2026
Behavioral round at Bytedance for a software engineering role, focused almost entirely on how you actually use AI in your day-to-day work. Not the vague 'what do you think about AI' stuff, they wanted specifics.
  • Walk me through how you use AI tools in your day-to-day engineering work. Which tools, for what tasks, and how do you validate what they produce?
  • Can you give an example where AI actually hurt your productivity rather than helped it?
  • How do you think about the risks of using AI tools at work, specifically around correctness, security, and intellectual property?

“This is broader than it sounds.”

View Post

ByteDance·Backend Engineer·Technical Phone Screen

Apr 2026
Backend phone screen at Bytedance that goes pretty deep into Redis and Go internals after a short intro. Not a casual chat, they clearly want specifics and will follow up on anything vague you say.
  • Walk me through the Redis use cases you've implemented and how you chose between them.
  • What are the differences between RDB and AOF persistence in Redis, and when would you pick one over the other?
  • How do Redis eviction policies work and what problems can they cause?
  • What are hot keys and big keys in Redis, and how do you deal with them?
  • How does Go's goroutine scheduler work?
  • How does garbage collection work in Go and how can it affect a backend service under load?
  • What are common concurrency bugs in Go and how do you prevent or detect them?
  • How do you use context for cancellation and timeout propagation in Go?
  • How do you handle errors idiomatically in Go?

“They didn't just want a list.”

View Post

ByteDance·Software Engineer·Technical Phone Screen

Apr 2026
Bytedance coding round for a Software Engineer role. The interviewer was a senior tech lead, strong communicator, and ran a clean interview. One hard algorithmic problem, solved it, and had a good back-and-forth during the Q&A at the end.
  • Given a 2D board of characters and a list of words, find all words that exist in the board (Word Search II).

“Went straight to a Trie and it clicked pretty fast.”

View Post

ByteDance·Product Manager·Hiring Manager Screen

Apr 2026
Third round at Bytedance that was supposed to be a hiring manager interview but turned out to be something else entirely. The interviewer asked me to use an online diagramming tool on the spot to walk through past work, which I'd never touched before, and the whole thing fell apart from there. Rejected about a week and a half later.
  • Walk me through your previous project work using this online diagramming tool (introduced on the spot during the interview).

“This was a disaster and I still cringe thinking about it.”

View Post

ByteDance·Software Engineer·Onsite - Coding / Algorithms

Apr 2026
Bytedance coding round for a software engineer role, just the one question: implement an LRU cache. Short and to the point, no fluff.
  • Implement a Least Recently Used (LRU) cache from scratch.

“Classic question but I still fumbled the eviction logic for a second.”

View Post

ByteDance·Software Engineer·Technical Phone Screen

Apr 2026
Bytedance SWE interview hit me with a classic BST validation problem. Nothing too wild but the details matter more than you'd think going in.
  • Given the root of a binary tree, write a function to determine whether it is a valid binary search tree.

“I jumped straight to checking left child less than root and right child greater than root, which is the classic wrong answer.”

View Post

ByteDance·Software Engineer·Technical Phone Screen

Apr 2026
Bytedance SWE interview with a classic stock price problem. Nothing too wild, but the pressure of doing it live is a different beast than grinding it at home.
  • Given an array of daily stock prices, find the maximum profit you can make by buying on one day and selling on a later day. Return 0 if no profit is possible.

“Classic problem, you'd think it's easy.”

View Post

ByteDance·Data Scientist·Technical Phone Screen

Apr 2026
Bytedance data scientist interview with a hypothesis-style case question tied to my own internship work. Pretty situational, which I wasn't expecting.
  • Imagine your company is about to launch the product you worked on during your internship. How would you design and conduct research to support that launch?

“Tricky because it sounds personal but it's really a research design question dressed up in familiar clothing.”

View Post

ByteDance·Machine Learning Engineer·Technical Phone Screen

Apr 2026
Bytedance ML engineer interview that went pretty deep into fundamentals. They wanted a full logistic regression implementation from scratch, not just theory, so if you're prepping for this role make sure you can actually write the math out in code.
  • Implement logistic regression from scratch: write the sigmoid function, binary cross-entropy loss, gradients for weights and bias, a training loop with configurable learning rate and iterations, plus predict_proba and predict methods. Optionally add L2 regularization and explain what it does.

“This was more involved than I expected for a phone screen.”

View Post

ByteDance·Software Engineer·Technical Phone Screen

Apr 2026
Bytedance SWE coding round, pretty much one meaty algorithm question that branched into a few follow-ups. Felt manageable but the follow-ups on indices and the divide-and-conquer variant caught me a bit flat-footed.
  • Given an integer array, find the contiguous subarray with the largest sum and return that sum. Expected O(n) solution.
  • How would you solve the maximum subarray problem using a divide-and-conquer approach, and what are the trade-offs compared to the linear scan approach?

“Knew Kadane's going in so the core answer came out clean.”

View Post