The Role
Build scalable, responsive React interfaces using JavaScript, HTML, and CSS. Develop reusable components, optimize rendering and Core Web Vitals, ensure cross-browser compatibility, write unit and end-to-end tests, debug browser issues, and implement PWA features using Web APIs, caching, and service workers. Collaborate with Product, Design, and Backend teams to deliver reliable, high-quality web experiences.
Summary Generated by Built In
Frontend Engineer Job Description
Not a fan of long JDs? take a minute to watch our video JD, it’ll give you a real feel of the role, growth and glimpse of your manager as well here : https://tinyurl.com/3wzr5nty
Position Overview:
Yesterday is history, tomorrow is a mystery, but today is a gift. That’s why we call it the present. - Master Oogway
Join our product engineering team as a Frontend Engineer and play a pivotal role in crafting fast, delightful, and reliable web experiences that power our platform. You’ll build modern UI using JavaScript + React, sweat the details in HTML/CSS, and ensure every feature ships with strong performance, testing, and cross-browser compatibility.
"Sometimes you gotta run before you can walk.” - Iron Man (and sometimes you optimize the render before you ship the feature.)
What You’ll Do ⚡
- Build product-grade UI: Develop reusable UI components and frontend features using JavaScript (ES6+), React, HTML5, and CSS3.
- Own responsive design: Deliver pixel-perfect, mobile-first experiences across breakpoints and devices.
- Ensure cross-browser compatibility: Make features work consistently across Chrome, Safari, Firefox, Edge (including real-device quirks).
- Performance optimization: Improve loading, rendering, and runtime performance using profiling tools and best practices (code splitting, memoization, caching, optimizing assets).
- Ship with testing confidence: Write unit/component tests and automated browser tests (E2E) to prevent regressions and improve release velocity.
- Master browser debugging: Diagnose UI issues using DevTools (network, performance, memory, layout/rendering) and fix problems at the root.
- Deliver strong Core Web Vitals: Monitor and improve LCP, INP, CLS and build performance budgets into day-to-day decisions.
- Work deeply with Web APIs: Use browser capabilities effectively (and safely) using [Web APIs](https://developer.mozilla.org/en-US/docs/Web/API).
- Build Progressive Web App features: Offline-ready experiences, caching strategies, installability, service workers, and resilient UX patterns.
- Collaborate cross-functionally: Work closely with Product, Design, and Backend to translate requirements into scalable frontend systems.
Why This Role Matters ?
“I can do this all day.” - Captain America (and you’ll want to, because great UX is addictive.)
You’ll be the person who turns complex product needs into simple, fast, and beautiful experiences. Your work directly impacts user satisfaction, conversion, retention, and trust; because on the web, every millisecond and every interaction matters.
Key Responsibilities
UI Engineering & Frontend Architecture
- Build scalable component systems and maintain clean frontend architecture.
- Write maintainable code with clear abstractions and well-defined component APIs.
- Collaborate on design systems and UI consistency patterns.
Performance, Reliability & Web Vitals
- Profile and optimize React rendering, bundle size, and runtime performance.
- Improve Core Web Vitals and prevent regressions through measurement and guardrails.
- Ensure stable behavior under real-world conditions (slow networks/devices).
Responsive Design & Cross-Browser Quality
- Implement responsive layouts and robust UI states (loading/empty/error).
- Validate cross-browser behavior and handle compatibility issues proactively.
Testing, Quality & Delivery
- Implement unit/component tests and browser automation tests.
- Participate in code reviews and uphold engineering standards and best practices.
Debugging & Web Platform Excellence
- - Debug complex browser issues using DevTools and performance tooling.
- - Build features leveraging modern Web APIs and progressive enhancement strategies.
Required Qualifications
Experience
- Strong hands-on experience building production web applications with React and JavaScript.
- Proven ability to ship responsive UI with high quality and strong performance.
Technical Skills (Must Have)
- JavaScript, React, HTML, CSS fundamentals (deep, not superficial).
- Data Structures & Algorithms: strong problem solving and ability to apply it to frontend performance and correctness.
- Responsive design: mobile-first layouts, modern CSS, and UX-first thinking.
- Cross-browser compatibility: practical knowledge and troubleshooting experience.
- Performance optimization: profiling + improvements with measurable outcomes.
- Testing: unit testing and automated browser testing tools.
- Core Web Vitals understanding and real-world optimization approaches.
- Browser debugging: strong DevTools skills across network/performance/layout/memory.
- PWA fundamentals and knowledge of offline/caching/service worker concepts.
- Web APIs knowledge and practical application.
Soft Skills
- Strong ownership, attention to detail, and a high bar for UX quality.
- Clear communication and collaboration with cross-functional partners.
- Continuous learning mindset; curiosity about the web platform.
Preferred Qualifications (Nice to Have)
- TypeScript (a plus).
- Accessibility knowledge (semantic HTML, keyboard navigation, ARIA basics).
- Experience with performance monitoring/analytics and error tracking in production.
- Interest in vibe coding: rapid prototyping and tool-assisted development; without compromising quality.
Interview Process (Sample)
1. Initial Screening: HR + role alignment
2. Frontend Fundamentals: JavaScript/React/CSS + debugging discussion
3. DSA Round: problem solving (time/space complexity, clean reasoning)
4. Practical Round: small UI feature with performance + testing expectations
5. Final Interview: collaboration, ownership, and growth discussion
Our Team Culture
“We are Groot.” - We work together, we grow together, we succeed together.
We believe in:
- Innovation First: ship, learn, improve; then ship better.
- Team Over Individual: strong reviews, shared ownership, no silos.
- Continuous Learning: the web evolves; we evolve with it.
- Making a Difference: quality UX changes how users feel about a product.
Growth Journey ?
Your journey with us will be like leveling up from building components to building systems:
- Level 1: Master our UI patterns and platform foundations
- Level 2: Own features end-to-end with great testing and performance
- Level 3: Lead complex frontend initiatives and mentor others
- Level 4: Become a frontend specialist who raises standards across the org
What We Promise
- Work that matters; real user impact
- Growth opportunities: tools, mentorship, and challenging problems
- Supportive team; strong engineering culture
- Work-life balance; sustainable pace, high quality
Skills Required
- Strong hands-on experience building production web applications with React and JavaScript
- Experience shipping responsive, high-quality, high-performance user interfaces
- Strong JavaScript, React, HTML, and CSS fundamentals
- Data structures and algorithms problem-solving ability
- Responsive design and mobile-first layout experience
- Cross-browser compatibility knowledge and troubleshooting experience
- Frontend performance profiling and optimization experience
- Unit testing and automated browser testing experience
- Understanding and practical optimization experience with Core Web Vitals
- Strong browser debugging and DevTools skills
- Progressive Web App fundamentals, including offline, caching, and service worker concepts
- Web APIs knowledge and practical application
- TypeScript experience
- Accessibility knowledge, including semantic HTML, keyboard navigation, and ARIA basics
- Production performance monitoring, analytics, and error tracking experience
- Interest in vibe coding and tool-assisted development
Am I A Good Fit?
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The Company
What We Do
CustomerLabs is a B2B SaaS company providing a customer data and first-party data operations platform for marketers. Its technology captures, transforms, unifies, and activates customer signals from websites, apps, servers, CRMs, and commerce systems, then sends them to advertising and analytics platforms. The company helps e-commerce, lead-generation, and agency teams improve attribution, audience matching, personalization, privacy controls, and campaign performance.
