We are looking for a Senior Android Engineer to join a small, single-threaded mission team that builds new business-calling capabilities into a mobile calling app. You will work in Kotlin, move quickly, test ideas with real users, and use AI tools as a normal part of how you build.
Android depth matters most. You also need to be willing to work in an agentic way and to communicate clearly with product, QA and backend colleagues.
** Please note this is a 6 month fixed-term contract
THE CLIENT AND THE PROJECT
Growing the business side of a calling app
Our client is an international calling company with a mobile app for consumers and small businesses. Its product and engineering team is small and spread across more than one location.
The mission is to grow the business-customer side of the product. The mission team will improve existing business features and add new ones to the core mobile app over roughly the next two quarters, working closely with a client backend engineer and the client's engineering, product and revenue leaders. Android is built first; iOS follows later.
Roadmap the engineer will work against
- First quarter: a more tailored app experience for business users, spending limits and top-ups, balance alerts and automatic top-ups, in-app, push and email messaging, and the design of shared business accounts.
- Second quarter: build of shared business accounts, usage history and reporting, support for several numbers, invoicing, and a web-based version of the calling feature.
Requirements
What you will do
- Design, build and ship Android features from the roadmap, working in short cycles with fast feedback from real users.
- Run quick experiments and A/B tests with the product manager. Some of what is built may be thrown away, so keep the work lean.
- Integrate new features with the client's core platform and the backend engineer's services.
- Work with the QA engineer so that automated tests are written alongside features.
- Use AI coding tools and agents across the development lifecycle, and help shape an agentic way of working for the team.
- Share code between platforms where it makes sense, preparing for later iOS work.
- Communicate progress, risks and trade-offs clearly to the client's product and engineering leaders.
What we are looking for
Must have
- Senior, hands-on Android engineering experience with Kotlin, shipping production apps to the Play Store.
- Experience integrating an Android app with a larger backend platform and APIs.
- A quick starter who can onboard fast and work flexibly in a small team.
- Active, regular use of AI coding tools and agents. A strong engineer who refuses agentic tools is not a fit.
- Clear written and spoken communication in English.
Nice to have
- Kotlin Multiplatform experience (the client is moving shared code to it).
- Experience with calling, VoIP, telephony or payments in a mobile app.
- Experience with A/B testing and experimentation in a product team.
- Experience with automated UI and unit testing on Android.
*Not a fit*
A strong engineer in another stack, such as .NET, with little Android background. The client ranks Android depth above agentic skill.
Who We Are
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