Senior Freelance Flutter Developer

Company Intro

At Toloka AI we create data that powers leading GenAI models and innovations. We work with frontier labs, big tech, renowned AI startups, enterprises and non-profit research organizations worldwide. We use a combination of Experts + Crowd + Tech Platform to teach AI models to reason and evaluate their efficacy and safety. We have experts in more than 50 different domains—from doctors and lawyers to physicists and engineers—and boast one of the most diverse global crowds, representing over 100 countries and speaking 40+ languages. We are a well-funded startup with an enviable portfolio of clients including Anthropic, Amazon, Microsoft, Poolside, Recraft, and Shopify.

Recently, we secured strategic investment led by Bezos Expeditions and Nebius Group with participation from Mikhail Parakhin, CTO of Shopify and board advisor to leading GenAI companies, who now serves as our Chairman of the Board. Our remote-first team is globally distributed around the world: USA, UK, the Netherlands, Israel, Czech Republic, Serbia, and more.

About position

We are looking for a Senior Freelance Flutter Developer to help build the next generation of our mobile platform.

Mobile is becoming a core part of how our ecosystem operates - from enabling real-time workflows in robotics-related projects (think: camera-assisted task execution on mobile devices) to powering large-scale user interactions and notifications.

You will work on products used by thousands of new experts joining every month and help define how mobile devices can be used to collect, process, and validate real-world data.

This is a high-ownership role where you will shape both the product and the technical foundation - from architecture decisions to shipping features that interact with cameras, media, and real-world environments.

We are not looking for a task executor - we are looking for someone who can turn ambiguity into working systems.

Key responsibilities

• Define and drive the technical direction of the mobile platform across iOS and Android
• Design and ship scalable, production-grade mobile applications used by tens of thousands of users weekly
• Build advanced mobile features involving camera, video, audio, and sensor data
• Develop solutions for real-world task execution and data collection on mobile devices
• Support non-standard device usage scenarios and edge cases
• Own the end-to-end delivery lifecycle:
• from idea and prototyping to production and iteration
• releases to App Store and Google Play
• reliability of critical user flows at scale
• Improve performance, stability, and user experience across the mobile stack
• Make pragmatic decisions between Flutter and native Android (Java/Kotlin)
• Work with hybrid architectures (e.g. WebView-based interfaces)
• Operate effectively in ambiguous environments
• Turn loosely defined problems into shipped, working solutions
• Proactively identify gaps and drive improvements

Qualifications

• Strong experience with Android development (Java/Kotlin) and Flutter
• Solid understanding of mobile architecture and design patterns
• Hands-on experience with Flutter state management, networking, and API integration
• Experience building and maintaining production-grade apps for Google Play and Apple App Store
• Deep understanding of mobile performance optimization, multithreading, and async programming
• Experience working with Android services, lifecycle, and background execution
• Familiarity with hybrid approaches (e.g. WebView integrations)
• Ability to work independently with ambiguous or loosely defined requirements
• Strong ownership mindset and ability to drive solutions end-to-end
• Understanding of product development workflows and cross-team collaboration
• Good written and spoken English (B2 or higher) - must-have for daily communication

What we can offer

• Freelance collaboration via the Ontop freelance platform.
• Flexible, fully remote work schedule.
• You’ll have the opportunity to work on highly innovative projects at the leading edge of AI development, together with a genuinely dedicated and dynamic team of experts.
• You’ll also be working on projects with customers that are AI industry leaders and well-known household names.
• Friendly community.