Fullstack Engineer (Frontend focus)

About the job

Type: Full-time, permanent

Location: Kutomotie 6 B, 00380, Helsinki

Application DL: 22.2.2026

About Zenniz

We’re building the future of tennis with innovative smart tennis court technology. The Zenniz smart tennis court system helps tennis players, coaches, and clubs with electronic line calling, match analysis, video tools, and gamified drills. Under the hood, our system turns raw camera frames into real-time line calls, match analytics, and rich post-match stories, but what matters most is how it helps people play, learn, and enjoy the game more.

The position

We’re expanding our team and are looking for a Fullstack Engineer (Frontend focus) to help shape the world’s best smart court experience. You’ll be part of our App Team, building and maintaining everything our users interact with from mobile and on-court tablet apps to LED displays, web applications, and real-time video overlays. We use Flutter across all platforms.

This role is ideal for a versatile engineer. You’ll mainly focus on frontend work, with opportunities to broaden your skills into areas like cloud functions or CI if that interests you. A big part of the role is working directly with our customers, listening to their input, and understanding the underlying needs behind their requests. Curiosity and a willingness to learn matter more than ticking every box. 

If you enjoy crafting polished user experiences, working on cutting-edge products, and combining technology with sports, you’ll feel right at home with us.

Our stack includes Flutter, Tailscale, Go, Google Cloud, and Firebase, but we don’t expect you to know everything already. What matters is that you enjoy learning, care about quality, and want to build reliable products used by thousands of players on and off the court.

What we’re looking for

We’re looking for a curious software engineer who enjoys building user-facing products and takes pride in delivering high-quality work. You care about how things look and feel to the user, and you’re motivated by seeing real people use what you build.

You may have experience with frontend development and modern UI frameworks, but we’re more interested in how you approach problems than in which exact tools you’ve used. If you’re comfortable learning new technologies and improving your skills as you go, you’ll fit in well. Experience with Flutter is a plus, but not a requirement.

We value engineers who take ownership of their work, test and improve what they build, and aren’t afraid to ask questions or suggest better ways of doing things. Working at Zenniz means collaborating closely with backend engineers, and customers, so clear communication and a willingness to listen are important.

You don’t need to be a tennis expert, but a genuine interest in tennis is important for this role. Background in tennis helps you better understand the context in which our products are used. We work in an international environment, so you should be comfortable communicating in English.

We welcome candidates with different backgrounds and levels of experience. If this role sounds exciting to you, we encourage you to apply even if you don’t meet every expectation listed above.

Why Zenniz

At Zenniz, you’ll work on a product that has a real, visible impact on how tennis is played and experienced. Our technology is used on courts around the world by players, coaches, and clubs who rely on it during training and competition — not someday, but every day.

Sports are at the core of what we do. We want to be the best product in our industry. We care deeply about performance, fairness, and improvement, and those values shape how we build our products and how we work as a team. You’ll join a group of people who are motivated by creating high-quality experiences and pushing sports technology forward. 

We’re a close-knit team that enjoys spending time together beyond day-to-day work. From tennis tournament trips and after-work sports to the occasional video game session, we value the shared experiences that build trust and make collaboration easier.

We offer a competitive monthly salary depending on experience, along with benefits and the possibility of stock options. If you’re excited about building impactful products at the intersection of technology and sport, Zenniz is a place where your work truly matters.

Practicalities

In this full-time and permanent position you will be employed directly to Zenniz. The start time in the role is as soon as possible. We value in-person collaboration and encourage regular time at our Helsinki office, while still supporting a hybrid way of working.

Interested?

Send us your resume and a short note on why you’d be a great fit. Please send your resume and possible requests for more information to careers@zenniz.com