Android Engineer London

We aim to create a world where sending and receiving money is effortless. Our app allows users to pay people, not numbers - no IBAN, account numbers, or sort code required. All you need is the recipient's name to send money.

Sling leverages blockchain technology to transfer in any currency almost instantaneously for a negligible fee. We're in 150 countries and the app is available in the Android and iOS app stores. Sling is from Avian Labs, Inc., created by product builders and engineers from Monzo, Square, and Cash App.

Our Android app is built entirely in Kotlin with Jetpack Compose from day one, so there's no legacy Java or XML code to maintain. We use modern libraries and architecture, including Apollo GraphQL for networking, Room for local storage, and Slack's Circuit framework to structure our Compose-driven UI. We've built our own Solana Kotlin library in-house to interface directly with the blockchain.

The codebase is about three years old and we're entering a phase of rapid growth. Android is a critical platform for Sling, and we need to scale the app to serve users across 150+ countries on a wide variety of devices. This means focusing on performance, stability, and an excellent user experience, even on lower-end Android phones. And because Sling deals with people's money on the blockchain, security and cryptography are super important in everything we do on Android.

We're looking for a Senior Android Engineer to join our small, experienced, and highly collaborative team. We want someone who is product-oriented and cares about how people will use and interact with the software they're building.

You'll be a key part of building and defining our product, our infrastructure, and our culture for years to come. We're looking for an engineer who cares about people, craft, and quality-and who likes to move fast.

• Design, build, and ship new features for the Sling Money Android app, working across the UI and platform stack.
• Collaborate closely with product managers, designers, and backend engineers to craft a great user experience from concept through launch.
• Optimize the app's performance and reliability across a broad range of Android devices, ensuring a smooth experience even on entry-level hardware.
• Improve and maintain core systems related to security and blockchain (Solana) integration.
• Participate in code reviews, testing, and iterative improvements to keep the codebase high-quality and scalable as we grow.
  
  

• You're an experienced engineer who has built high-quality consumer Android apps at scale.
• You have a drive to build and want to do it for billions of people, from the ground up.
• You want to help build a team, not just be a part of it. You're happy to take the extra time to explain things, provide actionable feedback, and level up those around you.
• You're a good communicator, both verbally and written.
• You're comfortable with ambiguity, both technically and organizationally. You're happy to tackle problems without a clear definition or solution.
• You enjoy owning problems from end-to-end, from the early exploration of the problem through to releasing things to customers.
• You like to share your work early and you're happy to put something out there when it's 70% done.
  
  

• Experience in fintech or the payments industry.
• Familiarity with GraphQL and the Solana blockchain (or other blockchain technologies).
• An eye for smooth, delightful Jetpack Compose animations and UI polish.
• Proven skills in Android performance optimization, especially with Jetpack Compose.
  
  

• Competitive salary and equity package
• Opportunity to be a core part of a fast-growing fintech startup
• Collaborative and innovative work environment with autonomy
• Free lunch in our breezy Shoreditch office and hybrid working flexibility
• Professional growth opportunities, team offsites, and events