GUARDIAN NEWS & MEDIA★4.6 (7)· London

Build the Guardian Android app using Kotlin, Java, Jetpack Compose, Coroutines & Flow, MVVM, Jetpack libraries, and modular architectures. As a Staff Engineer on the Apps Experience team, you will shape technical direction, architecture, and engineering standards across multiple teams for an app used by millions.

You'll build Voop's full-stack platform using TypeScript, React/React Native, Kotlin Multiplatform, Hono, Postgres, Pulumi/SST, Docker, AWS, and Kamailio. Voop creates a safe mobile network with device-integrated safeguarding and AI-driven risk detection, with its first product live protecting UK children. You'll ship production code across web, mobile, and backend services.

The role involves building and maintaining the company’s platforms,

Build the Guardian Android news app in Kotlin and Java, using Jetpack Compose, Coroutines & Flow, MVVM, WebViews, Jetpack libraries and modular architectures, with CI/CD and testing. As a Staff Engineer on the Apps Experience team, you'll set technical direction and mentor engineers across multiple teams.

JPMorgan★3.9 (20k)· London

Java/Springboot, Kotlin, DynamoDB, Aurora/MySQL, AWS, Kubernetes, and Kafka drive the event-driven microservices architecture. The team builds and maintains integrations with digital asset providers and infrastructure (on/off ramp) for J.P. Morgan Personal Investing’s mobile and web apps.

Develop mobile apps in React Native (iOS/Android) with TypeScript, Expo, and Jest, integrating with Ruby on Rails backend services over a JSON API and Postgres. You will join the product team building a market-leading platform that manages the end-to-end installation of home energy solutions like boilers, heat pumps, and solar panels for brands such as BOXT and E.ON Next.

Use React Native (iOS/Android) with Ruby on Rails, Postgres, and JSON APIs; work with TypeScript, Expo, Jest, and Git. You will build the platform managing end-to-end installation of home energy solutions for BOXT and E.ON Next. As technical anchor, you mentor junior engineers and lead mobile architecture.

React Native developer will work with JavaScript/TypeScript, APIs, and CI/CD to build and optimise mobile apps for iOS and Android. The role is with a FinTech undergoing a digital transformation programme, modernising core mobile products and improving user journeys.

Build cross-platform mobile apps with React Native + TypeScript and native Swift/Kotlin for hardware/sensor integrations, plus offline-first architectures. You will own mobile product development for an AI startup that builds custom, AI-native software modernizing field operations.

Platform Engineer role at Freetrade, working with Google Cloud infrastructure, Kubernetes, serverless, Terraform, and Node.js (TypeScript). The Platform Engineering Team builds foundational CI/CD pipelines, logging, observability, and security systems to support product, frontend, and data engineering teams.

You will work with Flutter, Dart, Firebase and Python to build and ship features across PuntoCare and cognitive stimulation games. Punto Health is an AI-powered platform for early detection of cognitive change and personalised care.

Work with Google Cloud, Kubernetes, serverless, Terraform, Node.js (TypeScript), and CI/CD pipelines. You'll join the Platform Engineering team at Freetrade, an investing platform, to treat the platform itself as a product—building the foundational infrastructure, observability, and security that Freetrade's own engineers rely on to ship.

Lead the transition from outsourced to in-house engineering, working with Ruby on Rails, PostgreSQL, Vue 2, Swift, Kotlin and AWS. As CTO of a personal trainer software platform with £2M ARR, you will define the technology roadmap, own architecture decisions and build the engineering team from the ground up.

Work with Android SDK, Java/C/C++, React/Ember.js/AngularJS, VoIP, P2P, Bluetooth, and voice recognition APIs. The role builds the Mobilus voice communication mobile app and platform, developing automatic multi-network switching and persistent voice channels for teams in extreme environments.

Work with Kotlin, SQL/noSQL, TensorFlow Lite, Coroutines, Flow, and REST/gRPC to build a production Android app for an AI-powered proactive smart assistant that handles multi-step workflows and real-world task completion.

Build and maintain iOS applications using Swift and SwiftUI, integrating AI features backend APIs and on-device inference with TensorFlow Lite. The team is building an AI-native proactive smart assistant that handles long-running workflows, multi-step reasoning, and real-world task completion for everyday users.

Build React Native identity-verification and onboarding experiences using JavaScript/TypeScript, component architecture, state management, and CI/CD pipelines. The identity engineering team owns the customer-facing front door of Zepz’s cross-border remittance platform, handling millions of users’ first contact and security checks.

You'll work primarily with TypeScript, Node.js, and PostgreSQL on GCP, designing and building scalable backend systems. The team develops and maintains a robust investment platform that powers features like mutual funds, bonds, and family investment tools.

You'll work with Java, AWS, GCP, Kubernetes (EKS), TeamCity, Terraform, Grafana, and microservice architecture to build Engine’s SaaS banking platform for financial institutions. As a Staff Engineer, you lead and mentor a high-performing engineering team, driving complex projects from inception to delivery.

Work with Java, AWS/GCP, Kubernetes (EKS), TeamCity, Terraform and Grafana on Engine's cloud-native microservice-based banking platform. The team builds the SaaS technology that powers Starling Bank, enabling banks worldwide. As Staff Engineer, you coach and lead a high-performing engineering team.

Java, AWS & GCP, microservices, Kubernetes (EKS), TeamCity, Terraform, and Grafana. You will build and enhance the Engine Platform, a SaaS banking technology powering global financial institutions, delivering new features and internal tooling for a cloud-native, microservice-based system.

Native Kotlin and Jetpack Compose development on a consumer-facing Android app for in-store grocery trips, running on a known device inside live stores. Integrates on-device edge AI (ML Kit, TensorFlow Lite) and uses AI coding tools like Cursor or Claude Code. Reports to the Head of Android.

Lead development of cross-platform mobile apps using React Native (Expo preferred), Dart, JavaScript/TypeScript, Git, and CI/CD. The team builds warpSpeed’s AI-powered productivity platform, delivering native iOS and Android experiences.

Koinly★3.0 (1)· London

Work with React 19, TypeScript, TanStack (Router, Query, Table), Radix UI, Mantine, Tailwind CSS v4, Vite, Vitest, Storybook, Highcharts, Sentry, Bun, and RabbitMQ on a data platform that reconciles crypto transactions and tax obligations for Koinly’s web application, with a React Native mobile app joining scope later.

Koinly★3.0 (1)· London

You'll work with React 19, TypeScript, TanStack, Radix UI, Mantine, Tailwind CSS v4, Vite, Vitest, Storybook, RabbitMQ, and Redis on a data platform that helps crypto investors reconcile transactions and file taxes. Koinly is a crypto tax calculator used by investors across chains, wallets, exchanges, and DeFi protocols.