Frontend Engineer

Welltech

Location: Cyprus, Spain
Job Type: full-time
Salary: Unknown
Posted: May 22, 2025

Job Description

Welcome to Welltech—where health meets innovation! 🌍 As a global leader in Health & Fitness industry, we’ve crossed over 220 million installs with life-changing apps, all designed to boost well-being for millions. Our mission? To improve the health of millions of people through intuitive nutrition trackers, powerful fitness solutions, and personalized wellness journeys—all powered by a diverse team of over 700+ passionate professionals with a presence across 5 hubs.

Why Welltech? Imagine joining a team where your impact on global health and wellness is felt daily. At Welltech, we strive to be proactive wellness partners for our users, while continually evolving ourselves.

What We're Looking For
We’re seeking product-oriented and mission-driven Frontend Engineers to join our Product Growth organization. In this role, you’ll work on highly visible parts of the user funnel—from activation to conversion—using modern technologies and experimentation to optimize engagement, trust, and revenue.

To support our mission of delivering smarter, more personalized health journeys, we've restructured our product organization around the user journey - two critical teams have emerged from this transformation: Purchase and Monetization.

These teams play a pivotal role in shaping how users first engage with our products, how we earn their trust, and how we convert interest into lasting value. Whether it's building seamless onboarding flows or optimizing pricing strategies, the work you do here directly affects millions of users and real business outcomes.

Key responsibilities:

Collaborate Across Functions: Partner with Engineers, QA, Product Analysts, and Product Managers to design solutions that solve real user and business problems

Build with Purpose: Develop high-impact features using a modern stack (React 18+, TypeScript 5+, Styled Components, React Query, Vite)

Deliver Quality at Speed: Build clean, tested, and maintainable code with performance, scalability, and UX in mind

Contribute to Team Excellence: Take part in thoughtful code reviews, documentation, and monitoring (Sentry, Datadog)

Learn & Iterate: Participate in A/B tests, analyze outcomes, and use insights to guide product and code decisions

Own What You Build: From development to deployment, be accountable for delivering features that perform reliably in production

Required skills:

Experience in frontend development (3+ years) at a product-driven company
Proficiency in JavaScript (ES6+), TypeScript, React, and Redux Saga
Strong understanding of REST APIs, Core Web Vitals, and responsive design
Solid grasp of software design principles (SOLID, design patterns, maintainable architecture)
Experience working in cross-functional, fast-paced agile teams and communicating effectively in English (C1)
A curious, user-first mindset with a desire to deliver intuitive, delightful digital experiences

Nice to have:

Experience working with experimentation platforms and running A/B or multivariate tests
Experience with Material UI and its design philosophy
Familiarity with Next.js, SSR, and performance optimization

The confidence to set up or optimize bundler configs (Webpack/Vite) from scratch

Candidate journey: ⭕️ Recruiter call ----> ⭕️ Live Code Design Review ---> ⭕️System Design Interview -----> ⭕️ Meet the hiring manager

✨ Why You’ll Love Being Part of Welltech:

Grow Together: Join a culture that champions both personal and professional growth. Here, you’ll thrive as we learn, evolve, and succeed together.
Lead by Example: No matter your role, your leadership matters. Every team member is empowered to inspire and make an impact.
Results-Driven: We’re all about achieving meaningful outcomes. It’s not just about the effort, but the difference we make every day.
We Are Well-Makers: Be part of a movement that’s creating a healthier, happier world. Together, we make well-being a reality!

🎯 Who is this job for?

This role fits a Mid-level Frontend Engineer with 3+ years experience in product-driven companies, proficient in React 18+, TypeScript, Redux Saga, and modern frontend tools like Vite. Candidates should be skilled in building scalable, high-performance UI with strong knowledge of REST APIs, responsive design, and software design principles (SOLID). They must thrive in agile cross-functional teams, have a user-first mindset, and be comfortable participating in experimentation and A/B testing to optimize user engagement.

💬 Potential Interview Questions

Describe your experience with React 18+ and TypeScript 5+.
I have 3+ years building scalable, maintainable applications using React 18 and TypeScript 5, leveraging hooks, context, and type safety to improve developer experience and app reliability.
How do you handle state management with Redux Saga?
I use Redux Saga to manage complex asynchronous flows by creating sagas that listen to dispatched actions and perform side effects, helping keep Redux state predictable and clean.
Explain your approach to designing responsive and performant user interfaces.
I implement mobile-first responsive designs using CSS and Styled Components, optimize rendering with React memoization, lazy loading, and focus on Core Web Vitals to ensure fast load times and smooth interactions.
What’s your experience working with REST APIs in frontend development?
I build robust API integrations using fetch or axios, handle error states gracefully, and use React Query to cache, update, and sync data efficiently.
How do you ensure code quality and maintainability?
I follow SOLID principles, use design patterns, write unit and integration tests, conduct thorough code reviews, and maintain documentation to keep codebase clean and scalable.
Describe how you participate in cross-functional collaboration.
I actively communicate with product managers, analysts, QA, and designers to clarify requirements, iterate quickly based on feedback, and ensure solutions align with user and business goals.
What experience do you have with experimentation and A/B testing?
I have worked with experimentation platforms to run A/B tests, analyze user behavior and metrics, and iteratively improve product features based on data-driven insights.
How comfortable are you with bundler configuration like Webpack or Vite?
I am confident in setting up and optimizing bundler configs from scratch, including code splitting, caching strategies, and build performance tuning.
Have you worked with Next.js and server-side rendering (SSR)?
Yes, I have experience building SSR apps with Next.js, improving SEO, initial load performance, and providing seamless user experiences.
How do you monitor frontend application health and performance?
I integrate tools like Sentry and Datadog to capture errors, monitor performance metrics, and proactively address issues to maintain high availability and smooth user experiences.

📋 Job Summary

Join Welltech, a global leader in health and fitness with 220M+ app installs, as a Frontend Engineer focused on enhancing user journeys in activation and monetization. Work remotely from Cyprus or Spain using React 18+, TypeScript, Redux Saga, and modern tools like Vite and React Query. Collaborate cross-functionally in a fast-paced, product-driven team to build scalable, high-impact features with a user-first mindset. Competitive salary, career growth, and a mission to improve millions of lives await you.