Liftoff Full-Time Software Engineer Technical Phone Screen Experience
Interview Experience
Phone Interview Outputting a matrix diagonally, not difficult. The first question was finding the shortest distance between two points in a graph. I mentioned BFS, but was asked if it could be faster
Full Details
Phone Interview Outputting a matrix diagonally, not difficult. The first question was finding the shortest distance between two points in a graph. I mentioned BFS, but was asked if it could be faster, so I used bidirectional BFS. I hadn't written it before, but luckily it wasn't difficult, and I wrote and tested it on the spot. The second question was about Eddington numbers, which I found online, similar to Likou Erqis. Parsing IPv4 and IPv6, which I found online, but with more conditions to consider than Likou's, making it very complicated, involving five or six cases. I barely finished it, and the interviewer said it was already very good. Completing a count store on the spot in 90 minutes, also found online. Talking with the hiring manager. Surprisingly, there was no system design question. Their company is similar to ByteDance, requiring passing each stage individually. Finally, I didn't hear back for over a month, thinking I had failed. It turned out the hiring manager felt I wasn't suitable for the position (even though he was the one who initially encouraged me to apply), so we talked to another team. This hiring manager said they would send out an offer later.
About This Question
This is a candidate experience report from a liftoff interview for a swe role during the phone screen round reported in 2025.
It covers the following topics: Graph, Bfs, System Design, Graph, System Design, Matrix .
Difficulty rating: Hard
Topics
About Liftoff Interview Reports
This question was reported by a candidate who interviewed at Liftoff. LeakCode aggregates interview reports from 10+ sources, including 1Point3Acres, Glassdoor, LeetCode Discuss, Blind, Reddit, Indeed, and Nowcoder. Each report is translated where necessary, deduplicated against existing entries, and tagged by company, role, round type, and reporting date.
Use this question as one calibration data point, not a memorization target. Companies typically rotate their question pools every 2-4 months; the exact wording of a 2024 question may differ from what you encounter today. The underlying pattern, difficulty level, and follow-up depth at Liftoff are the higher-signal extractions to take from this report.
For broader preparation context, the Liftoff interview process typically includes a recruiter screen, one or two technical phone screens, and a 4-5 round on-site loop covering coding, system design (at L4+ levels), and behavioral. Reports tagged on LeakCode show the round-by-round distribution and typical difficulty calibration. To browse questions filtered by round type and seniority, use the company hub linked above.
How To Practice This Type of Question
Solve similar problems on LeetCode under timed conditions (25-35 minutes per medium difficulty). The goal is pattern recognition: recognize the underlying technique (sliding window, two-pointer, BFS, memoized recursion, etc.) within 60-90 seconds of reading. Strong candidates verbalize their hypothesis out loud before coding, then iterate based on feedback. Weak candidates dive into implementation immediately, lose time on the wrong approach, and run out of time for follow-ups.
Companies update their question pools every 2-4 months. The exact wording of any given question may have been retired by the time you interview. Focus your prep on the pattern, not the specific problem. The patterns that appear in Liftoff reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Liftoff Round
Apply the standard interview round template: clarify requirements (2-3 minutes), state your approach out loud and confirm direction with the interviewer (3-5 minutes), code with narration (15-25 minutes), test with concrete examples including edge cases (5 minutes), discuss optimization or trade-offs if time permits (5 minutes). This template is universally accepted across FAANG and adjacent companies; deviating from it produces weaker interviewer feedback signal.
The single most predictive failure mode in Liftoff reports tagged "no hire": not asking clarifying questions. Interviewers are explicitly trained to weight this. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's written notes.