(Freelancer) Senior Mobile Developer (iOS / Android)

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- Gain control. Choose your projects, set your own rates, and work on your terms.

- Work on your terms. We mostly offer long-term projects (6+ months) for individual consultants and entire project teams.

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We are currently looking for a Senior iOS, and a Senior Android Developer who care deeply about application architecture, developer tooling, and testability. A customer of ours developing smart health tech solutions is looking for two senior professionals - one iOS and one Android expert - to help build and harden advanced simulation capabilities directly into the application layer.

If you love making complex app behavior reproducible, reliable, and lightning-fast in CI and local development, this is the project for you.

• Start: Summer 2026
• Duration: Until the end of the year (with a strong possibility for an extension)
• Allocation: 100%
• Location: Mostly remote (occasional visits to our Helsinki or Oulu offices are a plus)

Why join this project?

• Impactful tech: You will work on cutting-edge smart health tech solutions, improving software that impacts users' well-being.
• Unique technical challenge: This isn't just standard feature shipping. You will work at the exciting intersection of mobile engineering, testability, automation, and developer productivity.
• Future-proof engineering: You will help build a rock-solid testing foundation that enables faster iteration and the safe, accelerated use of AI/LLM coding tools.
• Great flexibility: Enjoy a fully remote setup from anywhere in Finland, with just occasional face-to-face meetups in Helsinki or Oulu.

Your responsibilities; As either our iOS or Android expert, your main focus will be building simulation capabilities into the application layer to make app flows reproducible from packaged inputs. You will:

• Build & harden simulation support: Enable deterministic, simulation-based execution using packaged input data to ensure runs are easy to diagnose and maintain.
• Improve Dev & CI workflows: Enhance the reliability, observability, and performance of simulation runs in both local development and CI environments.
• Design smart architecture: Create application-side integration points, hooks, and configurations for controlled backend interaction without compromising maintainability.
• Collaborate cross-functionally: Work closely with test tooling, backend, and QA engineers on simulation input formats, secure data handling, and automation flows.
• Support the team: Define practical simulation use cases for regression testing, platform comparison, and feature validation.

Your background & skills; to feel at home in these roles, you should have a strong track record in mobile engineering and a passion for automation, meaning:

• Senior expertise: Strong professional experience in mobile development - Swift for the iOS role, Kotlin for the Android role.
• Deep platform knowledge: Solid understanding of app architecture, state management, storage/persistence, networking, and lifecycles on your respective platform.
• Test & CI savvy: Practical experience building software that behaves reliably in automated test environments and CI-oriented workflows.
• Problem solver: Ability to debug difficult application lifecycle, data flow, and concurrency issues with good engineering judgment.
• Great communicator: Comfortable working across app, backend, tooling, and QA boundaries, and able to explain technical trade-offs clearly.
• Ideally also: Experience with simulation systems, fixture-driven testing, or deterministic/emulator-based execution, experience working on data-heavy consumer apps or health-tech products, familiarity with developer tooling, internal platforms, or automation, and an interest in how LLM-assisted coding and AI tools change engineering workflows and quality requirements.

Sounds familiar? Join us!

The path to joining our network and this project:

1. Send us an application - we will review it, and if everything looks good, we’ll invite you to a remote meeting.

2. Let’s have a chat and get to know each other!

3. Once we decide to continue the process together, we will invite you to our network, and you'll get to set up your profile in our internal system. Our project team will also reach out and have a more specific chat with you evaluating the fit to this project in more detail.

4. Tweaking a Witted CV in our system specifically for this project in close cooperation with you.

5. Interview preparations together with our project team, and then an interview with our client.

6. Once the client has selected you for the project; let’s get contractual things in order and get you started in your project!

This is where our journey begins!