Senior Frontend Developer

Reaktor's award-winning tech community is looking for a Senior Frontend Developer to join us in Helsinki.

If you thrive on solving complex human problems through streamlined front-end logic, value autonomy over hierarchy, and enjoy navigating the landscape of large-scale consumer products, this challenge is for you!

In this role, you will bridge the gap between technical excellence and strategic business goals, building impactful front-ends while serving as a trusted advisor to our clients.

Your daily tasks include:

• Collaborating with the client’s tech and business teams to identify and implement the most effective technologies for their specific goals.

• Building and evolving high-traffic web front-ends where performance, reliability, and scale are essential.

• Writing clean, maintainable code in daily partnership with designers and backend developers to ensure a cohesive product.

• Providing the client and the team with high-level technical expertise and acting as a trusted advisor for front-end architecture.

• Driving long-term codebase health by proactively improving performance, accessibility, and overall quality.

You are an experienced frontend developer who prefers staying hands-on, working on complex web applications and collaborating with non-technical stakeholders.

To thrive in this position, you’ll need:

• Senior level competency: We don’t have a hard limit with years of experience, but we’ve noticed that in this kind of Senior role, competencies we are looking for usually take several years to accumulate (e.g. 8+ years of hands-on experience).

• Previous experience working on large, consumer-facing web products to ensure a deep understanding of scale and complexity.

• Strong hands-on expertise in React, TypeScript, and JavaScript, with the ability to take full ownership of front-end work from implementation all the way to production.

• A good sense of design and a clear understanding of how front-end decisions directly affect usability and the user experience.

• Familiarity with web accessibility considerations and how they influence front-end logic and component design.

• Consultative mindset and comfort working in close collaboration with clients and non-technical stakeholders to bridge technical execution with business goals.

• Fluency in Finnish and English, both verbal and written.

• Readiness to work in a hybrid-model, min. 2-3 days/week at our or client’s Helsinki office.

Why join us?

For two decades, we’ve been developing qualities and capabilities for adapting, reacting, and supporting change – building Reaktor to hold up in a fast-paced environment while ensuring the well-being of our people.

While working at Reaktor, we’ll provide you with:

• To be able to impact how you work. Together with the client, your team chooses the approach, technologies, and methodologies you think will work best in any given situation.

• A community with as much support as your heart desires.

• A team that’s not only experienced but considerate as well – they all want you to succeed.

• A sustainable work-life balance and support for your daily life outside of work. (e.g., free moving day, Reaktor car share, sick child care services, office space to use for your private events, etc.).

• An opportunity to grow as a professional. In addition to the day-to-day work, we offer internal training courses, community events, and 15-minute coffee breaks to discuss hot topics in tech and design.

• A possibility to take part in more extended academy-like studies like Cloud Academy.

• 300+ hobby clubs, from winter swimming and running to knitting and archery, that bring people together outside of (and sometimes inside) office hours. Many of these are supported by Reaktor.

• Check more benefits & perks below.

Diversity, equity, and inclusion

Together, we are committed to making Reaktor an environment that embraces and values all of our employees for the whole of who they are. We encourage applicants from all backgrounds to apply, knowing that studies show that members of underrepresented communities don’t apply for jobs unless they fully satisfy all of the requirements. If you're thinking twice about applying for this reason, we invite you to send us your application anyway. You could be just the person we're looking for.

Read more about our DEI work here.

Interested? Drop us a line – We'll be happy to hear from you!

To apply for any roles at Reaktor, you don't need to submit a resume if you don't have one ready, feel free to share your LinkedIn, website, or portfolio instead.

We’ll be reviewing applications as they arrive and will move forward with candidates once we find the right fit, so don’t hesitate to apply. This position is open for applications until Sunday, the 22nd of February 2026.