Senior Native Mobile Developer - iOS or Android | Retail

Reaktor; Helsinki; Hybrid; EUR 90,000 - 120,000; Full time

Job summary

Reaktor in Helsinki is seeking an experienced Senior Native Mobile Developer to join our Retail Business Unit across Europe. You’ll work on native iOS and Android apps, craft polished UI animations, and collaborate with clients, designers, and engineers to deliver robust mobile solutions.

Responsibilities include ownership of testing and production quality, contributing to architectural direction, and guiding teams through discovery, delivery, and integration work.

Qualifications

• Strong experience in native iOS development using Swift and/or Objective-C.
• Strong experience in native Android development using Kotlin and/or Java.
• A testing ownership mindset - you take responsibility for the full development cycle, from implementation to ensuring features are defect-free and shipped to users.
• Experience with production app monitoring and troubleshooting.
• Experience engaging with multiple stakeholders to solve challenging, ambiguous problems.
• Fluent verbal and written English to collaborate in an international environment.

Responsibilities

• Develop native mobile applications either iOS or Android.
• Build polished mobile UI experiences, including high-performance animations.
• Work on mobile SDKs, integrations, analytics, ads, or attribution frameworks depending on the client project.
• Collaborate with clients and stakeholders to clarify requirements, autonomously driving initiatives across the client organization and guiding technical and business teams in selecting the right technologies for their needs.
• Contribute to architectural decisions and long-term technical direction.
• Participate in discovery, concepting, and iterative delivery, not just implementation.
• Take ownership of testing, debugging, monitoring, troubleshooting, and production quality.
• Occasionally contribute beyond mobile when the project benefits from backend, API, or cloud infrastructure understanding.

Skills

iOS native

Android native

Testing ownership

Production monitoring

Stakeholder collaboration

English proficiency

Tools

Swift

Objective-C

Kotlin

Java

Job description

Reaktor's tech community is looking for an experienced Senior Native Mobile Developer to join our Retail Business Unit in our European locations (Helsinki, Amsterdam, Lisbon).

If you thrive in native mobile development, enjoy solving complex challenges in multidisciplinary teams, and are curious to work in a low-hierarchy environment, you might just be what we're looking for.

You will join our Retail Business Unit, where you will support clients in at least one of the domains iOS or Android native mobile development.

Your daily tasks may include:

• Developing native mobile applications either iOS or Android
• Building polished mobile UI experiences, including high-performance animations
• Working on mobile SDKs, integrations, analytics, ads, or attribution frameworks depending on the client project
• Collaborating with clients and stakeholders to clarify requirements, autonomously driving initiatives across the client organization and guiding technical and business teams in selecting the right technologies for their needs.
• Contributing to architectural decisions and long-term technical direction
• Participating in discovery, concepting, and iterative delivery, not just implementation
• Taking ownership of testing, debugging, monitoring, troubleshooting, and production quality
• Occasionally contributing beyond mobile when the project benefits from backend, API, or cloud infrastructure understanding

To thrive in this position, you'll need:

Must-haves

• Strong experience in native iOS development using Swift and/or Objective-C
• Strong experience in native Android development using Kotlin and/or Java
• A testing ownership mindset - you take responsibility for the full development cycle, from implementation to ensuring features are defect-free and shipped to users
• Experience with production app monitoring and troubleshooting
• Experience engaging with multiple stakeholders to solve challenging, ambiguous problems
• Fluent verbal and written English to collaborate in an international environment

We notice that it usually takes several years of professional experience to build this level of depth across both mobile ecosystems.

Nice-to-haves

• Experience with SwiftUI and/or Jetpack Compose
• Experience with reactive programming
• Experience with Flutter
• Experience with distributing beta versions via App Store and Google Play
• Experience with publishing apps via the App Store and Google Play
• Familiarity with backend development, APIs, databases, or cloud infrastructure
• Interest in building polished animations and working closely with Motion Designers
• Finnish language skills

Adaptability

Willingness to work in a hybrid setup. This means balancing office, client premises, and remote work.

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:

The ability 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

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.