Senior/Staff Android SDK Engineer

Location: Germany

About the Role

We’re building a next-generation VPN platform that allows enterprises to seamlessly embed secure connectivity into their own apps. As a Senior/Staff Android SDK Engineer, you will own the development of Android SDK layers - the platform-specific code that powers VPN integrations for our own apps and  enterprise partners. 

This role is deeply focused on SDK and systems-level mobile engineering. You’ll work on networking, performance, and platform abstractions that enable reliable, secure VPN experiences at scale.

What You’ll Do

• Implement and maintain the Android SDK layer using Kotlin and VpnService API
• Collaborate closely with core SDK engineers to ensure consistent, clean API design across platforms

• Build abstractions that simplify VPN integration for external developers
• Optimize SDK performance for latency, connection stability, and battery efficiency
• Handle connection lifecycle management, error handling, and edge cases across devices and OS versions
• Contribute to SDK architecture, modularity, and extensibility
• Build and maintain demo integration applications
• Lead AI-assisted development with Claude Code. Designing prompts and workflows, orchestrating sub-agents, reviewing and validating generated output, and shaping how the team uses AI to ship faster without sacrificing quality
• Define and own observability, reliability, and security standards (Analytics, structured logging, alerting)
• Establish and uphold high engineering standards through code reviews, testing practices, and clear documentation
• Support enterprise clients for integration and platform-specific issues

We approach engineering through the following principles: Testing by default, always CI/CD, data and automation-centered, with security at the core. We empower our engineers to make their own decisions about the tools and technologies that best address the problems they are trying to solve. 

What We’re Looking For

• Proven expertise in Android (Kotlin, VpnService) & understanding of the Android networking stack
• Experience designing clean, stable, developer-friendly SDK APIs - you think about the integration experience, not just the implementation
• Comfort working beyond the Android ecosystem - for example iOS, cross platform technologies, Rust - transferable cross-stack experience is what matters most
• A modern view on AI-assisted engineering. Experience orchestrating, guiding, and supervising AI agents (Claude Code or similar) to deliver production-grade systems is highly important to us.
• Solid understanding in software design principles and architectures
• Strong problem-solving and debugging skills
• Excellent communication skills, equally comfortable in deep technical reviews and in front of enterprise customers
• High degree of ownership and the ability to operate independently with minimal direction

Nice to Have

• Experience in mobile SDK / library development 
• Experience with VPN technologies, authentication systems or secure networking
• Experience in the iOS ecosystem or cross-platform mobile technologies
• Experience working on B2B / white-label platforms
• Knowledge of mobile security best practices (encryption, secure storage, certificate pinning) 

What we Offer

• Work with a modern tech stack in a strong engineering culture
• Influence on technical decisions and room to innovate
• Continuous learning opportunities and support for professional development
• A motivated, collaborative team with flat hierarchies
• A strategic role with real technical influence and ownership
• A modern engineering culture with CI/CD, observability, and a strong code review culture
• Purpose-driven work: we value security, quality, and depth over quick hacks

How we’ll support you

We believe in fostering an environment that empowers decision-making at all levels. Our culture is rooted in the inverted pyramid approach, where the engineers, who have a deep understanding of the product and the customers, are the ones who have the knowledge and the authority to make impactful decisions. 

• We prioritize treating every team member with respect and promote open and constructive feedback, ensuring a culture of trust and transparency
• We encourage learning through experimentation and provide a safe space for everyone to learn from their experiences
• Our managers are dedicated to facilitating career growth and creating an environment that attracts and supports talented engineers

ExpressVPN, a Kape Technologies company, is an equal opportunity employer. We promote equal recruitment and employment opportunities, and do not discriminate based on gender identity and/or expression, age, race, color, disability, culture, religion or belief, family and/or marital status, sexual orientation, or other characteristics protected by applicable law. We celebrate a diverse and inclusive work environment in which applicants and employees are treated with respect and dignity, and excel based on personal merit, qualifications, experience, and performance.  

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Before you apply

• At the moment, we do not sponsor visas in the EU. For Hong Kong, we require at least two years of working experience and a university degree in a related field. For Singapore and the UK, we can only sponsor visas for mid-career or above.
• Please upload your resume as a PDF and do not include any salary or compensation information in it.

ExpressVPN is one of the world’s leading providers of online privacy and security services for consumers. Started in 2009, we’ve grown to have millions of active paying customers, a team of more than 700 people worldwide, and a brand recognized by hundreds of millions of people in 18 languages and more than a hundred countries. We see huge growth in our industry, and are gaining market share through strong execution.