Finished a Zoom frontend engineer interview loop a few months ago, mid-level SWE role focused on their client apps (web, electron-based desktop client). Sharing the breakdown.
Recruiter screen was fine: 30 min, background + LC warmup verbally (she asked me to describe how I'd approach a debounce implementation, no code). Then a take-home assessment. That part surprised me. Most companies at this level skip take-homes for SWE, but Zoom had a 3-4 hour React project: build a simplified video conference UI component with participant tiles, audio indicator, and a few state-management requirements. No backend needed, just frontend.
I used React 18, hooks, and plain CSS modules. They didn't care what styling solution you pick but they do read the code carefully. I added a brief README explaining my decisions, which I think helped.
The virtual onsite was 4 rounds:
Coding round: one algorithm problem (medium, intervals) plus a frontend-specific question about implementing a lazy-loading image component with Intersection Observer. The lazy-loading one was the more interesting one, know your browser APIs.
System design (frontend): design a real-time collaborative whiteboard feature for Zoom. They cared about: WebSocket event handling, optimistic UI updates, conflict resolution at the client layer, and handling reconnects gracefully. This round is where I saw the most signal from the interviewer, lots of follow-up questions. Study frontend system design specifically, not just backend distributed systems.
Behavioral: classic STAR. 4 questions, emphasis on cross-functional work and handling ambiguous requirements. One question specifically asked about working with design and how I pushed back on a design decision I thought was technically risky.
Hiring manager round: culture, growth, team setup. Learn what Zoom's actual product org looks like before this round. I got tripped up because I didn't know which team I was interviewing for specifically.
Overall the bar felt reasonable for a mid-level role. They're not trying to weed you out on algorithmic tricks, they want to see solid React fundamentals, browser API knowledge, and that you can communicate clearly.