Senior Front-end Engineer

About Welltech

A future with Welltech

Welltech’s purpose is to move each and every body to start and stay well for life! Every trend, every piece of feedback and data, every experiment, and innovative solution we introduce, fuels the way we unlock wellness for and with our users. While appreciating and celebrating who they are, we strive to help them make turn small choices into lasting joyful habits. And that makes us proud of every step they take on their journey to living well, every day.

Disrupting industry

We are an international tech company with origin from Ukraine, founded in 2015, and a fast-growing global player with five hubs across Europe. With more than 220 million installs of our apps, Welltech offers disruptive, engaging fitness and wellness solutions. We are genuinely committed to creating value and ensuring a workplace where our talented, diverse individuals feel they belong as we shape the future of the health and fitness industry. Everything we do is driven by our purpose and guided by integrity, a testament to the trust we build- today and tomorrow.

Spread across five dynamic hubs in Cyprus, Poland, Spain, Ukraine and the UK, with a team of over 700+ #wellmakers, we provide an opportunity for everyone who is passionate about making an impact in the wellness industry.

Position

We’re on the hunt for a Senior Frontend Engineer who’s ready to take ownership, lead with innovation, and build exceptional systems in the Monetization team—a core part of our new Product Growth & Monetization structure. If you're passionate about data-driven user journeys, experimentation, and highly optimized purchasing flows—this is something for you.

Our Monetization team maximizes user trust by creating seamless, transparent pricing experiences. We're a data-driven engine, constantly running experiments, refining strategies, and unlocking sustainable revenue growth. You'll work alongside experienced team members to evolve our monetization models and build products that matter—both for our users and our business.

Key responsibilities:

Collaborate across disciplines: Work closely with cross-functional teams including Frontend/Backend Engineers, QA, Product Analysts, and Product Managers to design, develop, and deliver innovative solutions that directly influence user experience and revenue. You won’t just ship code — you’ll shape how millions interact with our products. 

Engineer with purpose: Translate business requirements into performant, maintainable code that shapes user trust and monetization experience. 

Own your systems: Take responsibility for system performance, scalability, and data integrity. Spot issues before they happen and suggest smart fixes. Participate in monitoring (Sentry, Datadog).

Elevate the Standard: Be a champion of engineering excellence. Drive clean code practices, lead code reviews, mentor peers, and contribute to a culture of innovation. Share knowledge and bring strategic thinking into technical discussions.

Build with Best-in-Class Tech: Craft modern solutions using React 18+, React-Query, Styled Components, TypeScript 5+, and Vite. Help shape how we architect, deploy, and scale services used by a global user base. 

Your qualification

• Senior-level experience building and maintaining frontend applications in a product-first environment

• Mastery of JavaScript (ES6+) and TypeScript, with an eye for performance and maintainability

• Advanced knowledge of React and its ecosystem — you’re comfortable with Redux Saga, Core Web Vitals, and beyond

• A deep understanding of how the web works, including RESTful API integration, web security, and responsive UX patterns

• Solid grasp of software design principles — you live by SOLID and know how to apply design patterns pragmatically

• Experience implementing testing strategies

• Strong communication skills and fluent English (C1) — you're confident leading discussions and documenting decisions

• A passion for crafting delightful user experiences, and a mindset of continuous growth and learning

Will be a plus

• 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

What we offer

• 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!

Additional details

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

Check out some of our products

Muscle Booster — https://musclebooster.fitness/ 

Yoga-Go — https://yoga-go.io/ 

WalkFit - http://walkfit.pro