Hiring Frontend Engineers: The Complete Guide

What Frontend Engineers Actually Do

Frontend engineers spend their days translating design mockups into functional, interactive interfaces. When a designer hands over a Figma file, the frontend engineer figures out how to make it work across phones, tablets, and desktops—handling edge cases like slow networks, different browsers, and users who navigate with keyboards instead of mice.

The work breaks into three main areas. Feature development involves building the actual UI: forms that validate input, modals that trap focus properly, data tables that sort and filter without freezing the browser. Quality assurance means testing across browsers, optimizing load times, and ensuring the interface works for users with disabilities. Collaboration fills the gaps—working with designers to refine interactions, coordinating with backend engineers on API design, and reviewing teammates' code.

A senior frontend engineer at a company like Airbnb might spend Monday morning in a design review, the afternoon deep in React code, and end the day debugging why Safari handles a CSS animation differently than Chrome.

Skills Progression by Level

Junior engineers (0-2 years) can build components from clear designs and fix bugs in existing code. They write solid CSS and JavaScript, use Git comfortably, but need guidance on architecture decisions and complex state management. Don't expect them to know why one approach beats another—they're building that intuition.

Mid-level engineers (2-5 years) own features end-to-end. They can make architectural decisions for medium-complexity projects, review junior code effectively, and debug production issues without hand-holding. They're growing toward system-level thinking and cross-team leadership, but aren't there yet.

Senior engineers (5+ years) design frontend architecture for complex applications. They lead technical direction, mentor junior engineers, and optimize performance at scale. Critically, they influence product direction—pushing back on designs that would hurt users or proposing technical solutions that unlock new product possibilities. They document decisions, share knowledge, and think about business impact, not just code quality.

Core Technical Skills

Fundamentals Every Frontend Engineer Needs

Strong frontend engineers have deep fluency in HTML and CSS—not just "can make it look right" but understanding semantic markup for accessibility, responsive design patterns using Flexbox and Grid, and modern approaches like CSS-in-JS or utility frameworks like Tailwind.

JavaScript and TypeScript mastery is non-negotiable. This means ES6+ features used naturally, async programming with Promises and async/await, and TypeScript for anything going to production. A candidate who says "I don't really use TypeScript" in 2026 is behind the curve.

Framework depth matters more than framework breadth. You want someone who deeply understands React, Vue, or Angular—including component architecture patterns and state management approaches—rather than someone who's touched all three superficially.

Mid-Level Expectations

Mid-level engineers should understand testing beyond just "writing tests." They know when to use unit tests (Jest, Vitest), integration tests (React Testing Library), and end-to-end tests (Playwright, Cypress)—and crucially, which approach fits which situation.

Performance awareness means understanding Core Web Vitals, bundle optimization, and lazy loading patterns. They should be able to look at a slow page and identify whether the problem is network, JavaScript, or rendering.

Tooling familiarity includes build systems like Vite or Webpack, CI/CD pipelines, and developer experience optimization. They don't just use these tools—they understand why they exist and can configure them.

Senior-Level Expectations

Senior engineers think about architecture: monorepo strategies, micro-frontends (when they actually make sense, not just because it's trendy), and design system development. They make decisions that affect the whole frontend organization.

They also handle cross-cutting concerns like internationalization, security (XSS and CSRF prevention), and analytics implementation. These are the "boring" parts of frontend that separate production-ready code from demos.

Interview Focus Areas

Technical interviews for frontend engineers should emphasize practical skills over algorithm puzzles. Ask candidates to build a real component—a dropdown menu, a data table, a form with validation—and watch how they think through accessibility, keyboard navigation, and edge cases.

Good technical questions include: "Build a dropdown menu component. How do you handle accessibility, keyboard navigation, and outside clicks?" Strong candidates mention ARIA attributes immediately and think about focus management. Or try: "You have 10 components that need the same user data. How do you share it?" This reveals whether they understand the tradeoffs between React context, state libraries, and URL state.

Behavioral questions should probe collaboration and ownership. "Tell me about a time you disagreed with a designer's approach"—you want respectful pushback, user-focused reasoning, and ability to compromise. "Describe a feature you owned from start to finish"—look for thinking beyond code: architecture decisions, testing strategy, launch process, iteration based on feedback.

Common Hiring Mistakes

Testing algorithm skills over UI skills is the classic frontend interviewing mistake. Frontend is about building interfaces, not implementing binary trees. "Build this component" reveals far more than "reverse a linked list." If your interview process doesn't include any actual UI work, you're filtering for the wrong skills.

Ignoring design sense costs you the best candidates. Great frontend engineers have opinions about UX—they push back on confusing interactions, suggest improvements, and advocate for users. Pure coders who don't care about the user experience make worse frontend engineers, even if their code is clean.

Overweighting framework expertise leads to bad hires. React vs. Vue vs. Angular matters far less than JavaScript fundamentals, CSS mastery, and architectural thinking. A strong engineer learns a new framework in weeks. Someone who only knows React but has weak fundamentals will struggle when React patterns don't apply.

Skipping accessibility questions reveals candidates with incomplete skills. Accessibility isn't optional—it's a legal requirement in many contexts and a basic quality bar. Candidates who dismiss accessibility or claim "we can add that later" don't understand modern frontend development.

Recruiter's Cheat Sheet

When scanning resumes, look for framework expertise (React, Vue, or Angular) backed by production examples—not just "familiar with." TypeScript mentioned prominently is a good sign; it's standard in 2026. Performance optimization experience and testing framework knowledge (Jest, Cypress, Playwright) indicate maturity. Any mention of accessibility awareness suggests a candidate who thinks about users, not just code.