Senior Mobile Engineer (iOS/Android)

Senior Mobile Engineer (iOS/Android)

We are seeking an exceptional Senior Mobile Engineer to join our pioneering AI joint venture at the intersection of telecommunications and artificial intelligence. In this critical role, you will build our flagship user-facing application across both iOS and Android platforms, implementing our AI-powered dialer and assistant that seamlessly blends advanced voice AI capabilities with proprietary telecommunications network features. Your initial mission will be to lead the development of the core application, focusing on the AI-powered dialer and native call integration for our product launch. You will be responsible for developing the entire user interface, integrating deeply with native call functionalities of each operating system, and ensuring the application is secure, performant, and provides a polished and intuitive user experience.

Working in close collaboration with our AI/ML Engineers, Backend Engineers, and Telco Integration Specialists, you will shape the future of voice-based communication in our fast-paced, agile development environment. Your primary focus will be on building a seamless and responsive user experience, integrating our advanced voice services via well-defined APIs. While you will handle Real Time audio data, the core AI model development is handled by our dedicated AI/ML team.

Key Responsibilities
Application Development & Deployment

• Lead development of the native mobile application on both iOS (Swift) and Android (Kotlin), from technical design to App Store and Google Play Store deployment.
• Implement core dialer functions and the user interface for the entire call journey.
• Document technical specifications, API usage, and architecture decisions to support knowledge sharing.
• Ensure the application adheres to the highest standards of quality, including low crash rates and responsiveness.
• Implement the complete user interface for the entire application journey, including:

User Interface Implementation

Onboarding and voice cloning consent flow

Real Time AI call screening view

Post-call summaries

Telco benefit hub

• Develop Real Time visualization components for voice-based interactions, showing speech recognition progress and AI processing status.
• You will also contribute to our forward-looking roadmap, which includes building novel interfaces for emotional intelligence feedback and multi-modal AI interactions.
• Integrate deeply with native OS call handling services: iOS CallKit and Android's CallScreeningService to intercept, manage, and enhance the native call experience.
• Implement network-powered features that leverage telco integration for call quality optimization, security verification, and scam detection.
• Build secure voice identity systems with multilingual capabilities and cultural adaptations for target markets.
• Implement secure on-device storage for sensitive data like authentication tokens and user preferences, with transparent permission handling for contacts, microphone, and call logs.
• Implement local data caching for performance and offline access.
• Implement dual-privacy architecture supporting both cloud and on-device AI processing with transparent user controls.
• Create collaborative features for secure sharing of assistant access within family/team groups.
• Collaborate with Back End engineers to efficiently integrate and consume RESTful APIs for fetching data and orchestrating AI services.
• Work closely with Product Managers and UX/UI Designers to translate wireframes and user stories into a polished, performant, and intuitive mobile application.
• Bachelor's degree in Computer Science, Software Engineering, or a related field.
• 5+ years of professional experience in native mobile application development.
• Expert-level proficiency in iOS and Android development.
• Demonstrable, hands-on experience using native call-handling frameworks:
• Telecommunications & OS IntegrationSecurity & Privacy FeaturesCross-Functional Collaboration

Qualifications

Required Education & Experience

• iOS CallKit for call directory extensions and call management, and/or Android's CallScreeningService for call interception and control
• Experience building complex, consumer-facing mobile applications.
• Deep understanding of mobile performance optimization, memory management, and battery life considerations.
• Solid experience consuming RESTful APIs and working with data persistence on mobile platforms.
• Experience with version control systems (Git) and CI/CD pipelines for mobile applications.
• Strong focus on UI/UX implementation and performance.
• AI-assisted coding is a natural and strongly leveraged way of working.
• Deep understanding of iOS and Android platforms and their respective development ecosystems.
• Experience integrating RESTful APIs and WebSocket connections for Real Time communication.
• Knowledge of secure data handling practices on mobile devices, especially for voice and personal data.
• Familiarity with background processing and service integration for continuous voice monitoring.
• Experience with mobile UI/UX implementation focused on voice-first interaction patterns.
• Proficiency with local database solutions for caching and managing conversation context.
• Deep experience with Multithreading and concurrency to manage Real Time audio data streams for a responsive UI.
• Knowledge of audio recording, playback, and processing APIs on mobile platforms.
• Ability to implement proper error handling and crash reporting for production applications.
• Experience integrating speech recognition and text-to-speech services into mobile applications.
• Experience integrating APIs for services that manage multi-turn conversational state.
• Experience working with libraries or services for voice activation and wake-word detection.
• Knowledge of audio processing for voice quality enhancement on mobile devices.
• Experience building applications that interact with both on-device and cloud-based AI services.
• Understanding of best practices for voice user interface design.
• Master's degree in Computer Science, Mobile Computing, or related field.
• Experience leading a mobile development team or project.
• Proficiency in both iOS and Android development.
• Previous experience with voice assistants, conversational AI, or communication applications.
• Familiarity with modern AI technologies and their mobile implementation (eg, LLMs, on-device ML, voice biometrics).
• Experience working in the telecommunications industry or with telecom APIs.
• Experience with WebRTC or similar Real Time communication technologies.
• Knowledge of accessibility best practices for voice-based applications.
• Experience developing applications for international markets (Germany, Singapore, South Korea, United Arab Emirates).
• Familiarity with mobile analytics, A/B testing, and automated testing frameworks.
• solutions to complex problems.

Required Technical Skills
Experience with Voice & Audio Applications

Preferred Qualifications
This position is based in London for 1 or 2 days a week near to Moorgate and offers a salary in the region of £90-120K basic + exceptional package and bonus