went through the citadel frontend engineer interview loop earlier this year for a role on one of their trading UI teams in chicago. wanted to write this up because i couldn't find much detail on the frontend-specific process anywhere.
phone screen was with a recruiter, pretty standard. they asked about my background, comp expectations, and timeline. no technical questions at all. got scheduled for the technical screen about a week later.
technical screen (1 hour, video call) two interviewers. first 40 minutes was a coding problem: build a small interactive widget in vanilla JS or react, your choice. i picked react. the problem involved managing some stateful UI with specific event handling constraints. they cared a lot about correctness and edge cases, less about whether you used hooks vs class components. asked a few follow-up questions about browser rendering and how the virtual dom works.
last 20 minutes was more conversational: recent projects, how i've handled cross-team dependencies, something i'd built that i was proud of.
onsite loop (4 rounds, full day remote) round 1: another coding problem, this time more algorithm-focused. not a classic leetcode hard, more like a medium with a UI-specific twist. sorting + rendering a dynamic list with some constraint.
round 2: system design for a web application. they wanted me to design a real-time data dashboard, which honestly felt very on-brand for citadel. latency, websocket vs polling, state management at scale, handling stale data. this round went deep.
round 3: behavioral. classic STAR stuff. tell me about a conflict with a stakeholder, a time you shipped something imperfect, how you handle ambiguity.
round 4: a deep dive into one of my past projects. they wanted specifics: what decisions i made, what i'd do differently, how i measured success.
things that seemed to matter: knowing your browser internals, being able to reason about performance (paint, layout, reflow), and giving concrete examples in behavioral rounds. vague answers visibly fell flat.
overall the loop was thorough but not brutal. no trick questions, no leetcode hard grind. interviewers were engaged and asked smart follow-ups. heard back about a week after the onsite.