Senior Android Engineer (Native Integration & Security)

Senior Android Engineer (Native Integration & Security)

We 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.

In this role, you will be the owner of our most critical, user-facing feature: the Telco-Verified Security Shield. You will be responsible for the magic moment of our product, delivering an instant, network-verified trust indicator to a user's device in the moments before they answer the call. This is not a standard mobile app role; it is a deep, Real Time systems challenge that requires you to architect and implement a high-performance, secure, and reliable solution that integrates directly with the Android operating system's native call-handling services.

Your primary objective is to own the client-side implementation of our sub-500ms Time-to-Trust (TtT) metric. You will be the driving force behind the trust in our product, working at the intersection of native mobile engineering, Real Time data processing, and client-side security. This position offers a unique opportunity to build a category-defining security product from the ground up, leveraging proprietary, network-level data that no pure-OTT competitor can access.

Key ResponsibilitiesNative OS Integration & Performance

• Architect, build, and own the entire native call interception flow using Android's CallScreeningService to intercept and analyze calls as they ring.
• Design and engineer the high-performance Trust Indicator overlay, obsessing over every millisecond of client-side processing to ensure we meet our strict sub-500ms Time-to-Trust (TtT) metric.
• Implement the client-side logic to consume and display Explainable AI reasoning (eg, Recent SIM Swap Detected, Verified Business) provided by our Back End services.
• Build a robust, efficient, and scalable client-side API integration layer to consume Real Time security signals (like our proprietary Scam_Score) from the AI Core.

Security & Quality

• Implement and champion our mandatory Zero Trust security architecture at the client level, ensuring all network data and user PII are handled with the highest level of security.
• Define and enforce best practices for performance, code quality, and testing for the entire Android security stack.
• Work closely with the QA Engineer to build test harnesses and instrumentation to rigorously validate the sub-500ms latency target and ensure a false-positive rate of less than 1%.

Cross-functional Collaboration

• Partner with the Senior Backend Engineer (Application & AI Orchestration) to define the API contracts and Real Time data flow needed to power the Security Shield.
• Collaborate with the UX/UI Designer to iterate on a seamless, intuitive, and trustworthy user experience for the trust indicator and its explanations.
• As a foundational engineering hire, you will help define our Android engineering culture, mentor future hires, and set the standard for technical excellence.

Required QualificationsEducation & Experience

• Bachelor's degree in Computer Science, Engineering, or a related field.
• 5+ years of hands-on experience in native Android development, with a portfolio of high-performance, public-facing applications.

Required Technical & Android Skills

• Expert-level, production-grade experience with native Android development (Kotlin required).
• Demonstrated, deep expertise with Android's native call-handling APIs, specifically the CallScreeningService framework. This is a critical, non-negotiable skill for this role.
• Proven experience building high-performance, Real Time user interfaces that are deeply integrated with the Android OS.
• Strong understanding of mobile security principles and best practices, including secure data storage, network communication (mTLS), and threat modelling.
• Proficiency in consuming RESTful APIs and Real Time data streams (eg, WebSockets) in a mobile environment.
• Strong understanding of Android performance profiling tools and techniques to debug and optimize for latency.
• Experience with multi-threaded and asynchronous programming on Android.

Preferred Qualification

Advanced Education & Industry Experience

• Master's degree in Computer Science or a related field.
• Previous experience in the telecommunications, cybersecurity, or anti-fraud/anti-spam industries.
• Experience building applications for a global audience with localization and compliance requirements.
• Experience with the Android NDK (C++) for performance-critical operations.
• Familiarity with Real Time audio processing on Android.
• Deep knowledge of mobile network protocols and security.
• Experience building or integrating SDKs.

Advanced Systems & Security Expertise

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 with a guide between £110k-£140K basic + package.