Why pre-screen senior frontend engineers before the technical interview
The framework will render whatever you give it, including a component tree that re-renders on every keystroke and a bundle that takes eight seconds on a mid-range phone. Engineers worth hiring have measured that on a real device and know what caused it. A short screen asks what made one of their applications slow, which separates people who ship features from people who own an application.
What actually matters when screening Senior Frontend Engineer candidates
- 01
Technical proficiency
Check depth in React 18 and Next.js App Router: server components, streaming, suspense boundaries, TypeScript generics, state libraries like Zustand or TanStack Query, and hydration pitfalls.
- 02
Systems and trade-offs
Probe rendering strategy choices: SSR versus ISR versus static, bundle splitting, Core Web Vitals targets, image and font optimisation, and when they rejected a heavy dependency.
- 03
Evidence and rigour
Test their testing and measurement habits: Jest or Vitest, React Testing Library, Playwright end-to-end suites, Lighthouse or RUM data, Sentry traces, and how regressions were caught.
- 04
Collaboration and communication
Assess collaboration with designers and backend teams: Figma handoff, design system or Storybook ownership, API contract negotiation, code review standards, and mentoring mid-level engineers.
Pre-screening questions to ask Senior Frontend Engineer candidates
12 questions grouped by what they test. Ask the same set in every screen and score answers on a consistent scale, or send them as an async video screen and compare answers side by side.
Applications they shipped
3 questions01Can you describe a project where you used these frameworks in production?
Listen forAn application with real traffic, and their own components rather than the team's overall work.
Side projects only, or nothing that served real users at any meaningful scale.
02What is the biggest challenge you have hit with these frameworks?
Listen forA genuine technical difficulty with the investigation described, including what was ruled out.
Challenges described as learning curve, or no problem that required real diagnosis.
03Can you describe your experience with these frameworks?
Listen forDepth including how the framework behaves underneath, not just familiarity with its conventions.
Experience described by years, or no understanding of what the framework does behind the interface.
Rendering chosen deliberately
4 questions04Can you explain how server-side rendering works and when you would use it?
Listen forRendering strategy chosen per route based on data freshness, cost and search requirements.
One rendering approach applied everywhere, or the trade-offs of each not understood.
05How do you manage state in a large application?
Listen forServer state and client state distinguished, with global state kept minimal and justified.
Everything placed in a global store, or server data cached manually in client state.
06What is your experience with static generation and incremental updates?
Listen forBuild times and cache invalidation considered, with the effect on content freshness understood.
Static generation used without considering build time at scale, or invalidation not planned.
07How familiar are you with component state and effect handling?
Listen forEffects used sparingly with dependencies understood, and unnecessary re-renders recognised as a cost.
Effects used for everything, or dependency arrays adjusted until warnings stop.
Performance diagnosed
3 questions08Have you encountered performance problems in these frameworks, and how did you solve them?
Listen forProfiling on a real device with the actual cause identified, and the improvement measured.
Memoisation applied everywhere as a reflex, or performance work with no measurement.
09How would you handle rendering a large amount of data in the interface?
Listen forVirtualisation or pagination chosen deliberately, with the memory and interaction cost understood.
Thousands of rows rendered directly, or performance assumed acceptable without testing.
10Do you have experience with code splitting and bundle size management?
Listen forBundle size monitored over time, with dependencies reviewed before being added to the application.
Bundle size never measured, or heavy dependencies added without considering the cost.
Tested and maintainable
2 questions11Do you have experience with testing in these frameworks?
Listen forTests written where they earn their keep, focused on behaviour rather than implementation detail.
Coverage targets treated as the goal, or tests that break on every refactor.
12How do you handle errors and failure states in the interface?
Listen forError boundaries and loading states designed for, with failures reported rather than silently swallowed.
Errors caught and hidden, or no defined behaviour when a request fails.
How to score responses
Score every candidate on the same four criteria immediately after the screen. At this stage you are shortlisting for panel interviews, not making the final call.
Technical proficiency
35%5Explains server versus client component boundaries, caching directives and hydration errors from real code they wrote, not documentation summaries.
Systems and trade-offs
25%5Names measured trade-offs, for example cutting LCP or JS payload by a specific amount, and states what the choice cost them.
Evidence and rigour
25%5Cites before and after metrics from Lighthouse, Web Vitals or Sentry, and describes a bug their test suite caught pre-release.
Collaboration and communication
15%5Describes concrete review feedback given, a shared component library they maintained, and how they resolved a disputed API contract.
The framework renders whatever you give it, including a bundle that takes eight seconds on a phone. A one-way video screen asks why.
Try it on HirevireScreening FAQ
Process basics
How long should a pre-screening round for this role take?
Fifteen minutes across eight to ten questions, answered async. Enough to establish what they shipped, test their rendering and state reasoning, and hear a performance debugging story.
Should I include a coding exercise in the screen?
No. Use the screen for experience and reasoning, then a focused technical round for code. A take-home attached to a first stage loses strong candidates without adding signal.
Evaluating answers
What is the strongest signal when screening this role?
A performance problem diagnosed with measurement. Senior engineers name the cause and the tool. Anyone who optimised by guessing has not owned an application in production.
How do I judge their architectural judgement?
Ask how they choose a rendering strategy for a page. Real answers reason from data freshness and cost. Anyone who applies one approach everywhere has followed a template rather than decided.
Go deeper on this role
Sanat has been hiring since 2012 and watching the recruitment industry change up close ever since, and turned that screening process into Hirevire's video screening platform. LinkedIn
