You will build and evolve customer-facing interfaces for AI Virtual Agents using React, TypeScript, Next.js and Vite, and refactor the frontend into a scalable platform with a shared component library and design system. Unitary’s factory builds custom operations agents that complete complex workflows end-to-end in customer tools.

Backend engineers use Python, Django, Django-REST-framework, GraphQL (Graphene), Celery, Postgres, and AWS (Packer, Consul, Terraform). They build and maintain the AI-driven energy management platform that powers utilities and optimises renewable generation. The global engineering team is around 1,400 people.

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 will work with TypeScript on Bun, RabbitMQ, Redis, PostgreSQL, Vitest, Sentry, and Rust. The team owns the distributed data-processing backend that ingests, normalizes, and reconciles on-chain and exchange data for Koinly’s crypto tax calculation product.

Senior WordPress Developer role: build bespoke WordPress sites and apps using PHP, MySQL, ACF, WooCommerce, Gutenberg, JavaScript (ES6+), SASS/SCSS, Git, Composer, npm, Vite, CI/CD. You’ll also drive AI-assisted development (RAG, MCP, Copilot) and mentor junior developers.

Work across the stack with React, TypeScript, and Node.js or Golang on privacy-focused systems and architecture that keep users' location data inaccessible. As part of Wheely's small core-engineering team, you'll collaborate with Product Managers, Designers, and Software Engineers to shape solutions from concept through production.

You will build and scale White Circle's ecosystem partnerships across AI, cloud, infrastructure, and consulting. The company provides an AI safety platform that uses natural-language policies to test and enforce AI model behavior, and fine-tunes its own LLMs. You will work with the Head of Revenue to source, negotiate, and close partnerships driving revenue and distribution.

You will work with Vue.js, Vuex, Pinia, Vite, TypeScript, and real-time data tools (WebSockets, SSE) to build high-performance trading UIs. The role is on the team that continuously improves Interactive Brokers’ critical platform for automated trade execution and custody across global markets.

Head of Quality Engineering to own quality across the organisation, working with PHP, Kotlin, GO, Python, Typescript, React, React Native, GraphQL, Relay, PHPUnit, Behat, JUnit, Kotest, Jest, Maestro, K6, Datadog, Sentry, Incident.io, Grafana, AWS, Docker, Kubernetes, RabbitMQ, Argo, Github, and Github Actions. The role will lead the use of AI (LLMs) for testing and will manage a team of approximately two Quality Engineers while being hands-on with code and CI pipelines. Lendable builds technology for consumer credit and savings products.

You'll ship code across Jay (Python, FastAPI, pydantic-ai) and a Laravel 11 core, with a frontend of Next.js, Nuxt and Vue, on AWS, using Claude Code and an in-house AI engineer. The team is building an AI agent that handles home setup and evolves into a Home OS for post-move tasks. You'll be one of a small, senior, AI-native engineering team.

You'll work with Kotlin, Spring Boot, Python, FastAPI, Postgres, BigQuery, GCP (Kubernetes, Docker), RabbitMQ, Terraform, Grafana, Prometheus, and Datadog. Plum is a fintech app helping users automate savings and investments across 10 European markets, used by over 2 million people. You'll design scalable systems, mentor junior engineers, and collaborate across product and engineering teams.

Develops modern web applications using Angular, TypeScript, RxJS, and REST APIs on a cloud-native AWS platform. Works on a globally used flagship product, collaborating with product, UX, backend, and ML engineers.

You'll work with Java, Spring, AWS Kinesis/SQS/SNS, MongoDB, Redis, PostgreSQL, GraphQL, OpenTelemetry, Datadog, and AI tools (Claude Code, Claude MPM, in-house MCP server). The Dev Platform team owns the architecture and evolution of Duetto's core Java/Spring monolith, which processes millions of hotel rate decisions daily, driving domain decomposition and platform modernisation.

Build full-stack applications with TypeScript, React, NestJS, Prisma, PostgreSQL, and AWS on the Reap Direct team, which develops client-facing web and mobile platforms for stablecoin-powered corporate cards, payments, and expense management tools.

SHARE★4.0 (23)· London

You will work with FreeRADIUS (v3/v4), RADIUS protocols, MikroTik RouterOS BNG, Linux, Docker, Hono (Node.js), PostgreSQL, GitHub Actions, Loki, Pino, Sentry, NestJS, and Kafka to own Share's network-facing infrastructure — including the RADIUS proxy architecture, per-partner FreeRADIUS servers, BNG integration, and provisioning pipeline — as the company aggregates telecom infrastructure across Africa. This player-coach role will build and lead the systems engineering team.

You will work with React, Tailwind, Node.js, tRPC, PostgreSQL, and Elasticsearch to build and scale a B2B property data platform that integrates thousands of data sources. As a hands-on lead, you will provide architectural oversight across frontend, backend, and data infrastructure while mentoring senior and mid-level engineers.

Building TypeScript, Next.js, Supabase, Vercel, Tailwind CSS, shadcn/ui, AI/LLMs, and observability tools like PostHog and Sentry. This early-stage startup redefines how companies generate, manage, and grow revenue. As a founding engineer, you shape the product and technical direction.

Charles Tyrwhitt★3.5 (143)· London

You'll work with HTML5, CSS3, BEM, JavaScript, jQuery, and ISML templates on a Salesforce Commerce Cloud (SiteGenesis) storefront, and migrate to a headless PWA or Storefront Next stack using React, TypeScript, Tailwind CSS, React Router, Vite, pnpm, Git, and SCAPI/REST APIs. You'll build and enhance customer-facing ecommerce features and supporting the company's future frontend architecture.

You will work with TypeScript, React, Next.js, and Vite on SoundCloud’s desktop and mobile web surfaces. You will join a three-person feature team on the Revenue Group Web Team to build and maintain user-facing features for ads, subscriptions, payments, and creator commerce.

You will lead two cross-functional squads — Cards Experience and Cashier Experience — owning

You will work with FreeRADIUS v3/v4, RADIUS protocols, Linux, Docker, Hono, PostgreSQL, GitHub Actions, and monitoring tools (Loki, Sentry). You will own Share’s network-facing infrastructure—the RADIUS proxy, per-partner FreeRADIUS servers, BNG integration, and provisioning pipeline that authenticates ISP subscribers. As the player-coach VP of Systems Engineering, you will build and lead the systems engineering team as Share scales from 10 to 500 ISP clients.

You will work with React, TypeScript, Vite, TailwindCSS/SCSS, Node.js, NestJS, AWS (Lambda, API Gateway, S3, DynamoDB), and CI/CD tools like GitHub Actions. You’ll contribute to designing and developing eMoney and FX payment systems within the Alpha division.

Java, React (Vite, NX), Kafka/Solace/RabbitMQ, WebSockets/SSE, Rx, Kubernetes, and SQL drive a multi-year platform modernisation building real-time, low-latency, high-performance microservices for front office trading. You will combine hands-on engineering with technical leadership, shaping architecture and engineering standards.

You will work with Kotlin/Spring Boot, Python/FastAPI, Postgres, BigQuery, GCP (Kubernetes, Docker), RabbitMQ, Terraform, and monitoring tools like Grafana and Datadog. You will build backend systems for Plum’s AI-powered saving and investing app, which serves over 2 million users across 10 European markets.

Proton★5.0 (1)· London

You will work daily with C#, TypeScript, and Rust, also providing bindings for Swift and Kotlin, using tools like Grafana, Prometheus, Sentry, GitLab CI, and Playwright. The Drive Foundation team builds the SDK that powers Proton Drive, ensuring cross‑client consistency and serving as the backbone for the encrypted cloud storage service.