Senior Backend Engineer (Java)

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 are looking for a Senior Back-end Developer (Java) who is dreaming of developing ambitious tech products. You’ll join our Payments team, a core part of our tech organization that’s building a modern, internal payments platform from the ground up. Our mission is to streamline and future-proof payment operations across the entire business. We're not just maintaining systems—we’re rethinking how payments should work in fast-scaling products.

The team is a highly collaborative, cross-functional group with deep expertise in infrastructure, databases, distributed systems, and back-end engineering. We value autonomy, ownership, and knowledge-sharing, and we’re always looking for new ideas to make our systems smarter, faster, and more secure. You’ll have the opportunity to work on technically rich projects that have real, measurable business impact—and have a lot of fun along the way.

Key responsibilities:

• Collaborate across disciplines: Work closely with cross-functional teams including Frontend/Backend Engineers, Infrastructure, QA (SDET), and Product Managers to design, develop, and deliver innovative solutions that drive real impact.

• Design and implement robust systems: Translate both functional and non-functional requirements into scalable, reliable, and maintainable software. Your code will directly shape user experiences and system integrity.

• Build and operate microservices: Develop, deploy, and maintain high-performance microservices using Spring Boot. Own your services end-to-end—from design and implementation to deployment and ongoing support.

• Operate in cloud-native environments: Manage deployments and configurations across various Kubernetes clusters, ensuring smooth rollouts and minimal downtime in production and staging environments.

• Champion system excellence: Take responsibility for the performance, scalability, security, and data consistency of the systems your team owns. Proactively identify bottlenecks and propose architectural improvements.

• Drive engineering best practices: Promote clean code, test automation, continuous integration, and DevOps principles. Help elevate the engineering culture through thoughtful code reviews, tech talks, and collaboration.

• Mentor & lead by example: Provide guidance to team members, lead team level product and engineering initiatives, influence coding standards, support your team in making critical decisions

Your qualification

• Proven Java expertise: At least 5 years of hands-on experience building robust, high-performance applications using Java in production environments.

• Microservices architecture knowledge: A strong grasp of microservices principles, with a track record of designing and scaling distributed systems effectively.

• Spring Boot mastery: Deep, practical experience with the Spring Boot ecosystem—particularly with Spring MVC, RESTful services, Spring Data, Security, and messaging integrations.

• Database skills: Solid experience working with relational databases like PostgreSQL, including an understanding of relational database design, query optimization, and overall data architecture.

• Cloud infrastructure and Cloud-native deployment experience: Previous experience with AWS or another major cloud provider; practical experience deploying and managing services in Kubernetes across multiple environments (e.g., dev, staging, production).

• API and communication protocol fluency: Comfort working with REST, gRPC, messaging systems, and asynchronous communication patterns.

• CI/CD and DevOps mindset: A solid understanding of modern CI/CD pipelines, quality gates, and automation practices that support fast, safe releases.

• Quality-first approach: Demonstrated experience writing comprehensive unit, integration, and API tests for microservices-based systems.

• High proficiency in both written and spoken English, enabling seamless collaboration in an international team.

Will be a plus

• Fintech domain experience: Previous experience working on fintech products or platforms, with an understanding of industry-specific challenges such as security, compliance, payment processing, and subscription billing.

• Stream processing knowledge: Proficiency with Kafka and Kafka Streams for real-time data processing and event-driven architecture.

• Modern app design principles: Familiarity with The Twelve-Factor App methodology and its application in cloud-native service design.

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 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