Build and maintain the company’s platforms using JavaScript, Node.js, Next.js, Express.js, React/React Native, .Net 4.8/9/10, C#, HTML/CSS, and API Restful Services. You will develop both web and mobile applications, collaborating with the team while working independently.

You will build production mobile apps for iOS and Android using React Native, TypeScript, and integrate AI, natural-language features, Swift, Kotlin, and Python. The venture-backed startup creates AI-powered software that replaces manual workflows for industrial and operational teams.

You will own an existing production React/TypeScript application across web, iOS, and Android, integrating with Python/FastAPI backends and managing CI/CD pipelines. The team builds a computer-vision platform that turns video data into actionable insights. You will drive frontend architecture on a small, collaborative engineering team.

Foundation Partners Group★2.6 (165)· London

Typescript, Python, full-stack web development, frontend focus, offline support, observability, and testing across devices. You will build and scale consumer-facing production web applications for Flok Health, an AI-native healthcare company transforming care for MSK pain.

Senior Software Engineer role at Everfox, working with modern C++ on cross-platform desktop (Linux, Windows) and mobile (Android, iOS) apps, plus Java/Kotlin, Swift/Objective-C, Qt, GitLab, Docker, Kubernetes, and Python. You will build and maintain the end-point software layer for the Hardsec product line’s secure browsing and VDI solution, owning design, development, and delivery. You will also coordinate a small team of engineers and manage release planning across multi-platform shipped products.

React, Node.js, AWS, TypeScript, React Native, RESTful and GraphQL APIs, serverless architectures, CI/CD, PostgreSQL, DynamoDB, and AI tools such as Claude and GitHub Copilot. Build and ship digital products for a pre-IPO challenger bank serving mass affluent clients, owning full-stack work from architecture to production monitoring.

Smarkets★5.0 (2)· London

Build web and mobile apps with Next.js, React, React Native, TypeScript, Redux, React Query, WebSockets, and REST APIs, using Figma for design and GitLab with Kubernetes for DevOps. You will craft polished interfaces for Smarkets, which operates one of the world’s most sophisticated prediction markets for sports and political events.

Capital on Tap★3.9 (55)· London

You'll work with C#, .NET, .NET Core, Flutter, Dart, Riverpod, GoRouter, Kotlin, Swift, SQL Server, MongoDB, Firestore, GCP, Azure, and CodeMagic. You'll own backend services for the Banking and Repayments platform and contribute to iOS and Android mobile development.

Build full-stack mobile applications using React, Node.js, AWS, React Native, TypeScript, JavaScript, GraphQL APIs, serverless architectures, CI/CD, PostgreSQL, and DynamoDB. You'll design, develop, and ship digital products for Monument, a challenger bank serving the mass affluent, with ownership from architecture to production.

Depop★4.4 (61)· London

This Senior Backend Engineer role uses Scala (primary), TypeScript, Python, Play Framework, Kubernetes, PostgreSQL, DynamoDB, and Kafka. The Shipping Experience team builds and evolves the end-to-end shipping journey for buyers and sellers on Depop’s peer-to-peer circular fashion marketplace.

Build production-grade cross-platform apps with React Native, TypeScript, and native modules (Swift/Kotlin). You'll design offline-first mobile workflows with AI integration (LLMs, agents) and build backend services (Python a plus). The team is removing manual barriers in industries like aerospace, healthcare, and energy.

Deliveroo★3.3 (1.5k)· London

Lead a full-stack team (~7–8 engineers) building the real-time, back-office workspace used by 30,000+ support agents across Deliveroo, DoorDash and Wolt. The stack includes Go, Python or Node.js (backend), React (frontend), with cloud tooling (Kubernetes, AWS, Datadog) and an in-house chat platform handling tens of millions of conversations monthly.

Deliveroo★3.3 (1.5k)· London

Work with R/Python, SQL, and Cursor/AI tools to design experiments including A/B tests and causal inference. As a Senior Data Scientist on Deliveroo’s three-sided marketplace, you drive high-quality decision-making across product, operations, and platform teams.

Works with SAST, DAST, SCA, Burp Suite, OWASP ZAP, Semgrep, Python, Java, Kotlin, Go, JavaScript, and CI/CD pipelines (GitHub Actions

Proton★5.0 (1)· London

As a Senior Front End Engineer on the Standard Notes team, you will work with JavaScript, TypeScript, React, ES6, Playwright, Jest, and Grafana. The team builds a secure note-taking and productivity platform, developing features like encrypted search and cross-platform sync using end-to-end encryption. All Standard Notes codebases are open source.

Proton★5.0 (1)· London

Engineering Directors at Proton set technical direction and work with PHP (Symfony), Rust, Python, Swift, Kotlin, Jetpack, Typescript, React, C#, SQL, Redis, MySQL, and Ceph across mobile, desktop, web, and backend platforms. They lead engineering for one of Proton’s existing or upcoming products—such as Proton Mail, VPN, Calendar, Drive, or Pass—which provide private, secure, open-source tools to over 100 million users. The role involves managing a team of managers and driving DevSecOps practices.

Funding Circle★3.5 (53)· London

You will work with React Native, React.js, TypeScript, Firebase, Gradle, XCode, REST APIs, and CI/CD for app releases on iOS and Android. The role involves building and scaling a mobile app for Funding Circle’s fintech platform that uses data to provide fast funding to small businesses.

Ebury★3.3 (13)· London

You will work with React Native, React, TypeScript, Python, PostgreSQL, Redis, Expo pipelines, AWS, and Git. You join Ebury’s Mobile Platform team to evolve the mobile app by building features, services, and frameworks that empower product teams to ship efficiently while maintaining a unified customer experience.

Depop★4.4 (61)· London

Depop seeks a Backend Software Engineer for its Search Retrieval team working with Python or Scala, AWS, and modern cloud infrastructure. You'll collaborate with product managers, data scientists, and mobile/web engineers to build search and information retrieval systems serving 1M+ daily active users on Depop's peer-to-peer secondhand fashion marketplace.

Rightmove★3.7 (31)· London

You'll manage a team delivering secure, scalable cloud platforms and infrastructure supporting hundreds of engineers across mission-critical services at Rightmove, the UK's largest property portal. The role blends cloud operations, platform engineering, security governance, automation, and FinOps, requiring hands-on experience with GKE, Kubernetes, Terraform, service mesh, Kafka, Elasticsearch, IAC, Python, Go, and CI/CD pipelines. You'll lead strategy and execution while mentoring engineers, ensuring reliability, managing cloud costs, implementing governance frameworks, and embedding security controls across the platform.

JPMorgan★3.9 (20k)· London

You'll work with React, JavaScript, TypeScript, React Native, REST APIs, and GraphQL to build front-end solutions for Chase UK, JPMorgan's digital banking platform launching across the UK. The role involves designing and delivering cloud-native microservices applications while mentoring junior developers and collaborating with cross-functional teams in a flat-structure, tribe-and-squad organization.

JPMorgan★3.9 (20k)· London

You'll build and maintain web applications for Nutmeg (JPM Personal Investing's UK wealth management platform) using React, HTML5, CSS, JavaScript ES6, Jest/RTL, Webpack/Vite, Docker, Git, Jenkins, and GitHub Actions within a cross-functional team. The role involves delivering product features end-to-end, fixing defects, conducting code reviews, and ensuring accessibility, security, and performance standards across the web ecosystem powered by an internal React design system.

JPMorgan★3.9 (20k)· London

You'll work with React Native, TypeScript, JavaScript, Kotlin, Swift, REST APIs, and GraphQL to build cloud-native microservices for Chase UK's mobile banking platform. As a Senior Lead, you'll design end-to-end solutions, mentor junior developers, and drive architectural decisions across the full SDLC while collaborating with cross-functional teams in a flat-structure organization.

JPMorgan★3.9 (20k)· London

You'll work with JavaScript, TypeScript, ES6+, and preferably React and React Native to build mobile banking applications for Chase UK's digital bank. The role involves designing cloud-native microservices architecture and delivering end-to-end solutions within a flat-structure organization serving millions of customers. You'll mentor junior developers, conduct testing, and drive continuous improvement across the full software development lifecycle.

JPMorgan★3.9 (20k)· London

You'll work with React Native, TypeScript, and JavaScript to build mobile banking applications for Chase UK, JPMorgan's digital bank serving millions of customers across the US and UK. The role involves designing cloud-native microservices architecture, mentoring junior developers, and delivering end-to-end solutions in a flat-structure organization focused on startup-style agility and customer impact.