Mobile Software Engineer (ClimateTech)

London (Zone 1) / Hybrid | £40,000 - £45,000 + Equity

Most engineers spend their careers building things that won't matter in ten years. This isn't one of those roles.

The Mission: Disrupt. Reuse. Scale.

At Cauli, we're tackling one of the UK's most stubborn environmental problems: the 10.7 billion items of packaging waste generated every year — less than 9% of which is actually recycled. We're not tweaking the system. We're replacing it.

Applying IoT and AI-driven technology in reuse, we've already prevented over a million pieces of single-use waste. Now we're scaling — and we need a mobile engineer who wants to help build the infrastructure that makes reuse as easy as throwaway.

Why Join Cauli?

We're a small, ambitious team led by founders who are deeply in the weeds with you. You'll work directly with our Head of Technology, with real ownership over meaningful parts of our product — not tickets in a backlog.

We also know that asking you to take a mission-driven role means we need to reward you for the growth we're building together. That's why equity is a genuine part of your package here — not a footnote.

Our equity options are meaningful.

As an early team member, you'll receive options that reflect the ground-floor stage we're at. We're growing fast — and when Cauli wins, you win with us.

The Role

You'll be the driving force behind our mobile engineering, shipping new features and updates across our consumer and client-facing apps.

Day to day, this means:

Developing and maintaining our mobile applications, including our point-of-sale client app (Kotlin)
Completing the migration of our separate iOS and Android apps into a unified KMP codebase — you'll have real ownership of this from day one
Building a lightweight web app integrated with Apple and Google Wallets as part of our container tracking solution
Contributing to backend work in PHP/Laravel when needed — you won't be expected to be a backend specialist, but you should be comfortable exploring the codebase
Occasionally supporting our smart bin hardware software (Linux SBCs running Python) when the need arises

This is a broad, hands-on role — ideal if you like variety and want to see your work in the real world quickly.

Who You Are

We're looking for someone with roughly 1–2 years of professional mobile engineering experience. We care far more about what you've shipped and how you work than years on a CV.

You might be a strong Android engineer ready to own a multiplatform codebase, or someone who's already hands-on with KMP and wants more ownership. Either way, you're someone who takes pride in clean, production-quality code — and wants the work to mean something.

You'll need:

Production-level Kotlin skills
Solid native Android development experience
Working knowledge of (or genuine enthusiasm for) Kotlin Multiplatform — you should be comfortable picking up an in-progress migration and running with it
Comfort working across Android and iOS targets — deep Swift/UIKit expertise isn't required, but you'll need to work with KMP-generated iOS frameworks and handle basic Xcode/SwiftUI integration
REST API integration experience

These would make you stand out:

PHP/Laravel familiarity — even read-and-modify level
Any web development experience (HTML/CSS/JS or lightweight frameworks)
Exposure to Apple Wallet / Google Wallet integrations or QR-based flows
Python familiarity, for occasional crossover with our smart bin codebase
CI/CD experience (e.g. GitHub Actions)
Experience with payment SDKs or Stripe
A background in hospitality, food service, sustainability, or IoT — not required, but a genuine plus

Note on KMP: it's still a specialist skill. If you're a strong Kotlin/Android engineer who's actively working towards KMP and can show real enthusiasm for it, we want to hear from you.

The Rewards

We expect high performance, and we reward it well.

Equity Options: Competitive options as part of the salary package.
Time Off: 30 days annual leave (including bank holidays) + your birthday off + Christmas shutdown (around 35 days total).
Culture: A small, diverse, supportive team — regular socials, a founders-led environment, and work that matters.
Perks: Company pension (NEST), Techscheme, and Cyclescheme.

A Few Practicalities

Visa Status: You must currently have the right to work in the UK. Cauli Ltd is unable to offer visa sponsorship for this position.
Location: This role can be hybrid, but requires time in our London (Zone 1) office and frequent client visits/field days.