Mobile Software Engineer (£40k–£45k + Equity) at Cauli

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network. The next step is to speak to Jack. Job Title Mobile Software Engineer Salary £40,000–£45,000 + Equity Company Description Cauli is the UK's largest reusable packaging provider, led by Forbes 30 Under 30 CEO Josephine Liang. They utilize IoT and AI-driven technology to replace single-use waste at scale, already preventing over 1.6 million pieces of packaging waste for major clients like BT, the NHS, and the University of Surrey. Job Description Join a mission-driven climate tech startup as the lead for mobile engineering. You will own the transition to a unified Kotlin Multiplatform codebase, shipping features across consumer and client-facing apps. This hands-on role offers real ownership, direct collaboration with the Head of Tech, and the chance to build infrastructure that eliminates environmental waste. Location London, UK Why this role is remarkable

• Lead the migration of native iOS and Android apps into a unified Kotlin Multiplatform (KMP) codebase with high levels of autonomy and ownership.
• Join a fast-growing, founder-led team that has already scaled to 50+ sites and works with prestigious enterprise clients like BT and NHS Barts Trust.
• Receive meaningful equity options as an early team member, ensuring you share in the financial success of a company solving a critical environmental crisis.

What You Will Do

• Develop and maintain mobile applications using Kotlin, including a point-of-sale client app and consumer-facing tools used in the real world.
• Architect and execute the migration to a unified KMP codebase while integrating lightweight web apps with Apple and Google Wallets for container tracking.
• Support the broader tech ecosystem by contributing to PHP/Laravel backends and occasionally working with Python on Linux-based smart bin hardware.

The ideal candidate

• Has 1–2 years of professional mobile engineering experience with production-level Kotlin skills and solid native Android development expertise.
• Possesses a strong interest or experience in Kotlin Multiplatform (KMP) and is comfortable working across both Android and iOS targets.
• Demonstrates a versatile startup mindset, willing to touch backend code and hardware integrations while maintaining clean, production-quality code.

Who are Jack & Jill? Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate. How does this work?

• Jack's an AI agent for job searching and career coaching. He works for you.
• Jill is the AI recruiter working for the company. She recruits from Jack's network.
• If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives.

We never post fake jobs This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.