← Back to Directory

Meta interview notes, page 134 of 238

FAANG / Big Tech

Most of these Meta write-ups come from Software Engineers (1,194), then Data Scientists (489) and Product Managers (453). The most reported rounds are the technical phone screen (1,190), the product sense round (466), the system design round (255) and the behavioral / leadership round (205).

2377 interview notes · updated Jul 2026

Meta·Software Engineer·Onsite - System Design / Architecture

May 2026
Meta system design round, just one question about the Facebook newsfeed. Short and focused, which somehow made it more stressful.
  • Design the Facebook Newsfeed system.

“I'd done this one before so I felt okay going in, but I spent way too long on the feed ranking piece and barely touched storage or the fanout problem.”

View Post

Meta·Software Engineer·Onsite - Coding / Algorithms

May 2026
Meta SWE coding round with two problems, one tree traversal question and one string manipulation question, each with a pile of follow-ups. The follow-ups are where things get interesting and probably where they're actually evaluating you.
  • Given the root of a binary tree, group node values by vertical column using x-coordinates (left child decrements x, right child increments x). Within each column, nodes should appear top-to-bottom, with ties broken by left-to-right traversal order. Return a list of columns, each containing a list of integers. Walk through your algorithm, the data structures you'd use, and give a time and space complexity analysis.
  • Follow-up to the binary tree column grouping: how would you stream results column by column without storing the entire traversal in memory first?
  • Follow-up: if there are two nodes in the same row and column, how would you change the tie-breaking rule to sort by node value instead of traversal order?
  • Follow-up: how does your approach scale to trees with up to 100,000 nodes? What breaks and what holds up?
  • Given a string containing lowercase letters and parentheses, remove the minimum number of parentheses so the remaining string is balanced. Return any valid result. Provide an O(n) time solution and explain why it's correct.
  • Follow-up: can you solve the balanced parentheses removal problem in a single pass?
  • Follow-up: if in-place edits are allowed on the string, can you reduce extra space to O(1)?

“BFS with a hashmap from column index to list of values.”

View Post

Meta·Software Engineer·Onsite - Behavioral / Leadership

May 2026
Behavioral round at Meta for a software engineering role. All four questions were leadership and conflict-type, no coding involved. Pretty standard stuff but the priority disagreement question threw me a bit.
  • Tell me about a time you worked on a project with no guidance or direction. How did you figure out what to do?
  • Describe a piece of meaningful feedback you received. What was it, and what did you actually do with it?
  • How do you handle it when others push back hard on your ideas?
  • Give me an example of when you and your manager disagreed about project priorities. How did it get resolved?

“I had a decent story for this but I fumbled the structure a bit, spent too long on context and rushed the actual actions I took.”

View Post

Meta·Machine Learning Engineer·Technical Phone Screen

May 2026
Meta ML engineer interview with a classic tree problem. Not much context given but it felt like a technical phone screen type situation.
  • Given two nodes in a binary tree, find their first common ancestor.

“Knew this problem but still fumbled the edge cases a bit.”

View Post

Meta·Software Engineer·Technical Phone Screen

May 2026
Meta SWE coding round, one question on string manipulation with parentheses. Pretty standard algorithmic problem but the details matter more than you'd think.
  • Given a string of characters containing only '(' and ')', remove the fewest parentheses possible to make the string valid. Return any valid result.

“My first instinct was to just scan and count mismatches, but getting the actual removal right took a bit more work.”

View Post

Meta·Software Engineer·Technical Phone Screen

May 2026
Meta SWE coding round with a simulation-style problem about battery drain cycles. Nothing too crazy but the problem had some tricky edge cases if you didn't read it carefully.
  • Given arrays of battery capacities and their respective recharge times, and a total time limit t, determine how many batteries will be fully drained within that time.

“The example they give makes it look straightforward but I spent a few minutes confused about what 'fully used' actually meant.”

View Post

Meta·Data Scientist·Onsite - Product Sense / Strategy

May 2026
A Meta DS onsite that was essentially one giant product metrics case study disguised as six separate questions. The whole thing revolved around a friend-activity notification feature, and they went deep enough that I left genuinely unsure if I'd done well or completely bombed it.
  • You receive a notification that a friend is attending a local event. Define what 'high quality' means for this notification system: specify a North Star metric, three driver metrics, and three guardrail metrics with exact formulas, denominator definitions, and attribution windows. Also distinguish leading from lagging indicators.
  • Before building this feature, estimate adoption and size the opportunity using historical event data. The naive estimator averages the percentage of sign-ups who arrived with at least one friend across past events. What are at least four biases in that estimator, and how would you correct for them? Also show how you'd compute a 95% confidence interval for expected daily notification opens.
  • Justify the engineering expense for building this feature. Derive a break-even formula that links expected incremental opens, sessions, and retention to dev-weeks and infrastructure cost, and state the minimum detectable effect needed to proceed.
  • Describe a pre-launch evidence plan using concept tests, surveys, and analog notification benchmarks to predict CTR uplift. How would you adjust for response bias and population mismatch?
  • Design the A/B test for this notification feature: define the randomization unit, primary and guardrail metrics, sample sizing, and explain when cluster randomization is required due to network effects. How would you detect interference and what do you do if contamination is found?
  • If an experiment shows time-on-site increases but CTR on the notification decreases, how do you make a go/no-go decision? Walk through a metric hierarchy or utility function, including constraints on unsubscribe rates and notification volume.

“This is where I spent the most time and probably still left gaps.”

View Post

Meta·Software Engineer·Technical Phone Screen

May 2026
Meta SWE coding question involving filtering and aggregating employee counts across office locations. Pretty straightforward list manipulation problem but the tuple structure tripped me up a bit.
  • Given a list of office locations where each entry contains a list of employee counts and a boolean indicating whether the location is open, return the summed employee count for each open location in the original order.

“The problem itself is not hard but I fumbled the input structure at first.”

View Post

Meta·Product Manager·Onsite - Product Sense / Strategy

May 2026
Meta PM interview for their Payments Platform, one question that sounds deceptively straightforward but has a lot of moving parts once you get into it.
  • You're the PM for Meta's Payments Platform. How would you improve it, and what north star metric would you track?

“The north star part is what tripped me up.”

View Post

Meta·Software Engineer·Onsite - Behavioral / Leadership

May 2026
Behavioral round at Meta for a senior software engineer role. One question but it hit harder than expected.
  • Tell me about a significant failure or major project setback you were involved in.

“I went in thinking I'd just talk about a bug that caused an outage, but the interviewer kept pushing until I got to something with real organizational scope.”

View Post