How to hire a Frontend Engineer

Frontend skill varies a lot between candidates with similar resumes. Take two developers with three years of experience. One knows how rendering works. The other has spent three years copying examples from a component library. They are very different hires. The best clue is how they think about performance, state management, and edge cases. Listing framework features tells you little.

Four things matter. Framework depth: do they know why a component re-renders, as well as how to stop it? Performance awareness: do they think about bundle size, lazy loading, and rendering cost before you ask? Design fidelity: can they build a design exactly, including spacing, animation timing, and responsive behavior? Accessibility basics: do they use semantic HTML and support keyboard navigation?

For consumer products, look for three more things. Comfort with responsive design, since many users are mobile-first. Experience with slow networks: do they build for poor connections? Working with design: can they talk through trade-offs with a designer? A good hire does more than copy the design pixel for pixel.

A strong frontend interview has three parts. First, a component-building challenge. Give the candidate a real UI component to build, such as an autocomplete, a sortable data table, or a drag-and-drop list. Score their code structure, edge cases, and keyboard accessibility. Second, a debugging exercise. Show them a page with a performance issue or a visual bug. Ask them to find the cause. Score how they search for it, as well as whether they find it. Third, a design trade-off conversation. Describe a case where the ideal design costs a lot to build. Ask how they would talk it through with the designer and PM.

Testing algorithm skills instead of UI skills. A frontend engineer's job is building interfaces. It is rarely solving graph problems. Use a skill-based assessment that asks them to build a component. Skip the abstract algorithms. Some candidates ace dynamic programming but cannot build a clean autocomplete. That person is not a strong frontend hire.

Ignoring accessibility. If your product is hard to use with a keyboard or screen reader, you lose users. You also risk legal trouble. Ask candidates about semantic HTML, ARIA attributes, and keyboard navigation. If they have never thought about it, your team will need to fill that gap.

Not checking for mobile-first thinking. For many consumer products, most users are on mobile. Some engineers design for desktop first and then squeeze it onto a phone. That solves the problem backwards.

Skipping the collaboration round. Frontend engineers work closely with designers and backend developers. An AI voice interview can test how they talk and work with others before the manager round. A strong coder who cannot discuss trade-offs with a designer slows the team down. So does one who cannot agree on an API shape with a backend developer.