Mobile Software Engineer – Kotlin Multiplatform, London

About the role

Join a mission‑driven climate tech startup that is replacing single‑use packaging with IoT and AI solutions. As a Mobile Software Engineer you will lead the migration to Kotlin Multiplatform while delivering features that have already prevented 1.6 million pieces of waste. This role sits at the heart of a fast‑growing team, working closely with the technical lead to shape sustainable mobile infrastructure.

Key responsibilities

• Lead the development and maintenance of consumer‑ and client‑facing mobile applications.
• Drive the transition from native Android/iOS apps to a unified Kotlin Multiplatform codebase.
• Build lightweight web components that integrate with Apple and Google Wallets for container tracking.
• Collaborate with backend engineers on PHP/Laravel services and support Python‑based software for smart‑bin hardware.
• Work directly with product and design teams to ship high‑impact features quickly.

Required profile

• 1‑2 years of professional mobile development experience with production‑level Kotlin.
• Strong foundation in native Android development and enthusiasm for Kotlin Multiplatform.
• Ability to work in a startup environment, tackling problems across the full stack.
• Interest in sustainability and climate‑tech solutions.

Required skills

• Kotlin
• Kotlin Multiplatform (KMP)
• Android SDK
• iOS development, SwiftUI
• Apple Wallet / Google Wallet integration
• PHP, Laravel
• Python
• REST APIs

What we offer

• Competitive salary £40k‑£45k plus equity in a high‑growth startup.
• Ownership of the mobile roadmap and a pivotal role in a sustainability mission.
• Opportunity to work with a Forbes 30 Under 30 founder and major enterprise clients such as BT and the NHS.
• Hybrid work environment with a London office base.