just wrapped up the CrowdStrike frontend engineer loop last month. posting because most CrowdStrike interview content is backend/security focused and frontend info is sparse. this was for a mid-level role on their platform UI team (the Falcon console, not an external product).
the loop: 5 sessions.
OA first. two coding problems, pretty standard HackerRank stuff. they were not frontend-specific. vanilla algorithm questions. don't expect DOM manipulation in the OA, it's general coding. this tripped me up mentally because i expected React, got arrays-and-trees instead.
javascript deep dive. this was the most interesting round. they went hard on the language, not the framework. closures, prototype chains, event loop, promises vs async/await under the hood. one question i didn't nail perfectly: explain what happens when you await a promise that's already resolved. i got it mostly right but fumbled the microtask queue explanation. study the event loop if you're prepping. also: how does the browser handle reflow vs repaint, and when does it matter for performance.
frontend system design. design a real-time dashboard that shows security alert counts across thousands of endpoints, updating every few seconds. i talked through WebSocket vs polling, how i'd handle state updates without re-rendering the entire component tree, virtualization for long lists, debouncing/throttling. they were engaged. the key is tying your decisions to actual user experience, not just technical elegance.
React/component round. live coding in a shared environment. build a filterable data table with sorting. they gave me a fake API. i used hooks, nothing fancy. they cared about code organization and whether i was handling edge cases (loading state, empty state, error state). spend 10 seconds on each state before you start.
behavioral. tell me about a time you improved performance of a UI. tell me about a disagreement with a designer. standard.
what surprised me: they care more about browser fundamentals than React specifics. makes sense for a complex security product where you're not just slinging CRUD UIs. the performance angle came up in multiple rounds.
offer i got: base $145k, Austin. RSUs $140k/4yr. around $180k TC year one.