Senior Mobile Flutter Developer

Senior Mobile Flutter Developer – UI / Performance / Optimisation - 3 Month Contract

Role Overview

• Senior hands-on Flutter Mobile Developer responsible for building high-quality, scalable and performant iOS and Android applications.
• Strong focus on UI/UX implementation, animation, responsiveness, performance optimisation and application speed.
• Experience taking mobile applications from requirements and design through development, testing, App Store/Google Play deployment and production support.
• Able to work closely with Product, UX/UI, Backend and QA teams.

Technical Requirements

• Strong commercial experience with Flutter and Dart.
• Proven experience building and maintaining production iOS and Android applications.
• Strong understanding of Flutter architecture, widgets, layouts, state management and responsive design.
• Experience with state-management approaches such as BLoC/Cubit, Provider, Riverpod or equivalent.
• Strong knowledge of REST APIs, JSON, authentication and integration with backend/microservices.
• Experience integrating WebSockets / Socket.IO for real-time functionality.
• Experience with push notifications, deep linking, analytics and third-party SDK integrations.
• Strong Git, CI/CD and mobile release management experience.

UI / UX Development

• Strong eye for detail and ability to convert Figma/UI designs into pixel-accurate Flutter interfaces.
• Build responsive and consistent UI across different screen sizes and devices.
• Experience with:
  • Complex layouts
  • Custom widgets
  • Animations and transitions
  • Gestures
  • Bottom sheets/modals
  • Forms and validation
  • Lists and grids
  • Image/media handling
  • Dark/light themes
  • Accessibility
• Develop reusable UI components and maintain a consistent design system.
• Focus on smooth interactions, responsiveness and excellent user experience.

Performance & Optimisation — Key Focus

• Strong understanding of Flutter performance optimisation and mobile application profiling.
• Identify and resolve:
  • Slow screen rendering
  • UI jank
  • Dropped frames
  • Excessive rebuilds
  • Memory leaks
  • High CPU usage
  • Slow API responses
  • Large application size
  • Excessive battery/network usage
  • Slow startup times
• Experience using Flutter DevTools and profiling tools to identify performance bottlenecks.
• Optimise widget trees, state management, rendering and rebuild behaviour.
• Optimise scrolling and large lists using appropriate Flutter techniques.
• Efficient image loading, caching and memory management.
• Optimise API calls, network requests and local data storage.
• Implement appropriate caching and lazy loading strategies.
• Improve application launch time, screen load time and perceived performance.
• Understand native iOS/Android performance considerations and platform-specific optimisation.
• Ability to measure performance improvements rather than relying on subjective assessment.

Application / Domain Experience

Experience developing one or more of the following is highly desirable:

• Social media: profiles, feeds, posts, comments, likes, followers, notifications, media and sharing.
• E-commerce: product catalogues, search, cart, checkout, orders, inventory, promotions and customer accounts.
• Payments: Stripe/Adyen/PayPal or equivalent, payment flows, webhooks, refunds and transaction status.
• Rideshare / mobility: driver/rider apps, GPS/location tracking, maps, driver matching, trips, ETA, pricing and real-time updates.
• Chat & messaging: real-time messaging, conversations, notifications, online status, read receipts and media sharing.
• Experience across multiple application types is strongly preferred.

Real-Time & Location Features

• Experience implementing real-time functionality using Socket.IO/WebSockets.
• Real-time notifications and application state updates.
• GPS/location services and background location where applicable.
• Maps and location-based functionality.
• Handling poor/intermittent connectivity and reconnection.
• Efficient management of frequent location/network updates without negatively impacting battery or performance.

Code Quality & Engineering Standards

• Strong understanding of:
  • Clean Code
  • SOLID principles
  • DRY
  • Separation of concerns
  • Reusable components
  • Design patterns
  • Maintainable architecture
• Strong code review and Git practices.
• Write clean, readable, testable and maintainable Dart/Flutter code.
• Understand technical debt and actively improve existing codebases.
• Strong understanding of application security and secure API/authentication practices.

Testing & Quality

• Strong understanding of the SDLC and mobile application testing.
• Experience with:
  • Unit testing
  • Widget testing
  • Integration testing
  • End-to-end testing
  • Regression testing
  • API testing
  • Performance testing
  • Device/OS compatibility testing
• Ability to build automated test coverage around critical functionality.
• Strong focus on preventing regressions and maintaining application stability.

CI/CD & Release Management

• Experience with mobile CI/CD pipelines.
• Automated build, test and deployment processes.
• Experience with App Store and Google Play release processes.
• Familiarity with tools such as GitHub Actions, GitLab CI, Bitrise, Codemagic or equivalent.
• Understanding of app signing, certificates, provisioning profiles and environment configuration.

Senior-Level Expectations

• Strong problem-solving and debugging skills.
• Takes ownership of features from design → development → testing → release → production optimisation.
• Able to investigate performance issues and provide measurable improvements.
• Comfortable reviewing existing applications and identifying technical/performance bottlenecks.
• Works effectively with UX/UI designers, backend developers, QA and Product teams.
• Mentors other developers and contributes to Flutter/mobile development standards.
• Strong focus on UI quality, speed, stability, scalability and overall user experience.

Essential

• Strong commercial Flutter/Dart experience.
• Production iOS & Android development.
• Excellent UI implementation skills.
• Strong understanding of mobile performance optimisation.
• Experience with REST APIs and backend integrations.
• Socket.IO/WebSockets experience.
• State management.
• Automated testing.
• Git and CI/CD.
• Strong software engineering and SDLC knowledge.
• Proven ability to optimise existing applications and demonstrably improve speed and performance.