Senior Flutter Developer

About On The Spot:

We bring startups and disruptive tech companies to the local market, offering engineers the opportunity to work on innovative, high-impact products. Join us and become a member of their R&D team while we take care of employment, HR support, a benefits package, and an enjoyable work environment.

About the team:

Finonex is a company building modern mobile trading and financial applications across multiple brands from a shared Flutter codebase. The team focuses on creating accessible, secure, and user-friendly trading experiences powered by cutting-edge technology, supported by 24/7 service.

About the role:

We are looking for a strong, hands-on Senior Flutter Developer to join our Mobile R&D team and help build our mobile trading applications.

This is a hands-on engineering role. You'll design and build high-quality features across Android and iOS, working within an established multi-flavor architecture and to a high engineering standard, as part of a team led by our Mobile Team Lead.

The ideal candidate takes strong ownership of their work, writes clean and maintainable code, and thrives in a fast-moving, regulated financial environment.

Please note that candidates for this position are expected to work in alignment with the Israeli team: Sunday-Thursday — work days, Friday-Saturday — days off.

Responsibilities:

Software Development

• Design, develop, test, and maintain high-quality features for Android and iOS in Flutter.
• Write clean, well-structured, testable code that follows the team's architecture, patterns, and coding standards.
• Contribute to integrations such as real-time market data, charting, analytics, and third-party financial SDKs.
• Work within the existing multi-flavor / multi-brand build and release process.
• Troubleshoot and fix production issues, and help keep the apps performant and stable.

Quality & Testing

• Participate actively in code reviews - both giving and receiving constructive feedback.
• Write unit, widget, and integration tests to keep quality high.
• Contribute to app reliability and observability (crash-free rates, performance).

Collaboration & Delivery

• Collaborate closely with Product, Design, Backend, and QA to deliver business objectives.
• Deliver predictably within sprints, with honest estimation and clear communication of progress and risks.
• Communicate proactively and clearly in English with a distributed, cross-country team.

Requirements:

• 5+ years of professional software development experience.
• 4+ years of hands-on Flutter development on production applications (Flutter as a primary, day-to-day skill - not occasional or secondary).
• Strong command of Dart and modern state management (BLoC, Riverpod, and Provider).
• Solid working experience within multi-flavor / multi-environment Flutter apps.
• Working knowledge of native Android and iOS - build configuration and platform-channel / SDK integration.
• Experience with REST APIs and real-time communication (WebSocket or similar).
• Strong ownership, autonomy, and problem-solving skills.
• Excellent written and verbal English — a must (daily communication with the Israel-based team).
• Availability to work Sunday-Thursday, aligned with the Israeli team — a must.

Nice to have:

• Experience in fintech, trading, forex/CFD, financial services, or another regulated industry.
• Experience with the Firebase suite (Crashlytics, Remote Config, Performance, Analytics).
• Experience with product analytics / attribution (e.g. Mixpanel, AppsFlyer).
• Experience with charting libraries (e.g. ChartIQ) and engagement SDKs (e.g. Braze).
• Familiarity with FVM, monorepo workflows, and GitLab CI.
• Experience with automated / integration testing and AI-assisted development tools.
• Experience working in distributed / international teams.

Benefits:

• Paid vacation — 20 business days per year, 100% sick leave payment (up to 10 days), 5 sick days per year;
• Equipment provision;
• Partially compensated educational costs (courses, certifications, attendance of professional events, etc.);
• Care package: Luxmed health insurance;
• English classes 2 times a week (online);
• MultiSport card 50% reimbursement company/employee;
• Full legal and accounting support in Poland if requested.