Senior Android Engineer

Job DescriptionSenior Android Engineer (UI/UX & Welcome Manager)OverviewWe are seeking an exceptional Senior Android Engineer to join a newly-founded joint venture backed by five of the world's leading telecommunications companies. Our mission is to restore trust in voice communication by building a network-native intelligence layer to combat the global epidemic of voice fraud and AI-driven scams.This is a rare opportunity to be a foundational hire, shaping the future of a product designed to protect hundreds of millions of users. We are building two core products: the Telco-Verified Security Shield (our primary, pre-call fraud detection) and the Personal Welcome Manager (our premium, AI-powered call screening experience).As the Senior Android Engineer for the Welcome Manager, you are the User-Facing Owner of our AI innovation showcase. This isn't just another UI/UX role; you will be the primary architect of a novel conversational interface. Your challenge is to build the magic: the live transcription, the mid-call intervention, the post-call summaries, that defines our premium user experience. You will own the app that we will showcase to the world at Mobile World Congress (MWC) 2026, and your work will be the primary driver for our monetization strategy.Key ResponsibilitiesConversational UI Architecture: Own the end-to-end development of the Personal Welcome Manager's conversational interface on Android. You will build a fluid, intuitive, and polished user experience from the ground up.Designer-in-Lockstep Collaboration: Work hand-in-glove with our dedicated UX/UI designer, engaging in rapid daily iteration to translate high-fidelity, interactive prototypes into pixel-perfect, production-ready code.Real Time Data Streaming: Engineer the high-performance live transcript view, which displays the AI-screened conversation as the phone is ringing. This involves consuming Real Time streaming text data from our Back End AI orchestration layer via WebSockets.Mastering Perceived Performance: Implement the critical mid-call intervention feature, allowing a user to seamlessly accept a call from the AI agent. You will become an expert in designing for our < 1000ms V2V (voice-to-voice) latency budget, ensuring the entire UX flow feels fast and responsive.API & Backend Integration: Partner with our Back End (Application & AI Orchestration) engineers to define and integrate the client-side APIs and data models required to power the Welcome Manager's features, from live transcription to post-call entity-extracted summaries.MWC Demo Ownership: Be directly responsible for the polish, stability, and performance of the Welcome Manager application for its critical debut at MWC 2026.Cross-Functional Partnership: Collaborate closely with the other Senior Android Engineer (who owns the native CallScreeningService and Security Shield overlay) to ensure a seamless and unified user experience between our two core products within a single application.Required Qualifications? Education & Experience? Bachelor's degree in Computer Science or a related field, or equivalent practical experience.? 5+ years of hands-on experience in native Android development, with a strong portfolio of shipped, consumer-facing applications. ? Required Technical & UI/UX Skills? Deep expertise in native Android UI/UX development, including Kotlin and modern frameworks (eg, Jetpack Compose, Coroutines, Flow).? Demonstrated experience building complex, Real Time, data-intensive user interfaces (eg, chat applications, financial dashboards, Real Time streaming apps).? Strong experience integrating with Back End APIs and services, particularly consuming Real Time data via WebSockets, gRPC, or similar protocols.? Proficiency in translating high-fidelity designs (eg, Figma, Sketch) into beautiful, performant, and maintainable code.? A strong understanding of Android UI performance optimization, memory management, and threading models.? Experience with the full mobile development life cycle, from ideation and prototyping to testing, release, and maintenance.Preferred Qualifications? Advanced UI/UX & Conversational AI? Prior experience designing or building conversational interfaces (eg, chatbots, voice assistants).? A strong portfolio that explicitly showcases beautiful, complex, and highly responsive mobile UIs you have built.? Relevant Technical Experience? Familiarity with Android's native call-handling APIs (eg, CallScreeningService, ConnectionService), as you will be integrating closely with the engineer who owns this.? Experience with performance testing and profiling Android applications to hunt down and eliminate bottlenecks.? Knowledge of mobile application security best practices.? Industry & Environment? Previous experience working in a fast-paced, agile startup environment.? Experience in the telecommunications or voice AI space.This is a permanent position with hybrid working of two days a week in the central London office and the rest WFH. The salary is very much Dependent on experience