finished the xAI frontend loop earlier this year. sharing because the frontend-specific info is basically nonexistent online and most of what's out there is general SWE stuff that wasn't quite accurate for my experience.
background: 4 years frontend, mostly React, some Vue. i was applying for what they described as a 'product engineer' role with heavy frontend component.
recruiter screen: standard. they emphasized this role was going to be building UI for Grok-facing products and internal tools for the research team. both needed. the recruiter said they care about engineers who can go from design to shipped without a lot of intermediate steps.
phone screen (60 min, one interviewer) this is where it got interesting for a frontend role. half the screen was a JavaScript fundamentals deep-dive. not framework stuff. core JS: closures, event loop, promise chaining, how prototypal inheritance actually works. i haven't been quizzed on the event loop since my first job interview years ago so this was a bit of a wake-up call.
the second half was a UI implementation problem. they gave me a figma link and asked me to implement a specific interactive component in plain JS or React, my choice. i went React. the component was a typeahead search with debouncing and a custom dropdown. they watched the whole thing. they cared about how i structured state, how i handled the edge cases (empty results, loading state, error state), and whether i added accessibility attributes without being prompted.
onsite (3 rounds, no DS/algo round) react architecture: we talked through how i'd structure a large feature with complex shared state. got into context vs redux vs zustand territory. not a gotcha quiz, more of a 'how do you think' conversation. performance: they gave me a slow-rendering component and asked me to diagnose and fix it. profiler usage, memoization, virtual list for long lists. real debugging scenario. system design (frontend-flavored): design the client-side architecture for a real-time collaborative document editor. not the backend, just the frontend. state sync, conflict resolution in the UI, offline support. this was the hardest round.
things to know: they care about core JS more than framework magic. if your react knowledge is entirely framework-level and you've never thought about what's happening underneath, study that. accessibility came up repeatedly, not as a checkbox but as a thing they actually care about. performance tooling: know chrome devtools profiler, react devtools profiler, and know what causes unnecessary re-renders.
overall a solid loop. more rigorous than i expected for a frontend role at a small company.