Citi★3.9 (21k)· London

You will work with TypeScript, React, HTML5, CSS, JavaScript (ES6+), Chromium/Electron/OpenFin, FDC3, REST/WebSocket APIs, Kafka/Solace/Tibco, and CI/CD with Jenkins. The team delivers pricing solutions and trading GUIs for Citi’s Foreign Exchange business. You will provide technical leadership, mentor junior engineers, and drive AI integration.

You will build scalable server-side logic using JavaScript, TypeScript, and Node.js in a microservices architecture on AWS with Kubernetes, Terraform, Kafka, and Snowflake. You will join the MMH team within the Martech domain, which orchestrates campaign delivery across email, push notifications, and personalised content for all Sainsbury’s Group brands. The team includes 7 engineers.

Develop backend services using Node.js, Python, Java, C#, PHP, and Ruby on Rails, with databases including MySQL,

Python, FastAPI, Docker, DuckDB (nice-to-have), JSON Schema, Git, and RESTful APIs. You will design and ship ETL pipelines that transform raw bank data into the FIRE regulatory reporting standard. Suade is a regtech SaaS company automating compliance and risk solutions for financial institutions.

You will work with JavaScript (TypeScript), React, Redux, RX JS, NPM/Yarn, webpack, CSS, HTML, Azure DevOps CI/CD, and Java. As a senior developer on the FM Digital Channels team, you will build Blade, the bank's strategic in-house pricing, execution, and trade processing platform for Financial Markets.

Lead Python Developer role using Core Python, Flask, VueJS, JavaScript, CSS, HTML, SQL, AWS, Terraform, Docker, and serverless components, with CI/CD and Agile practices. The developer builds, enhances, and supports production applications within UK public sector programmes, collaborating with delivery, product, and data teams.

Work with Python, FastAPI, Docker, DuckDB, JSON Schema and Git to design, build and ship client ETL pipelines that map raw bank data onto the FIRE regulatory reporting standard. You will maintain a shared ETL framework, write validated mapping code, and mentor junior engineers at Suade, a regtech SaaS company automating compliance for financial institutions.

BNY★3.5 (5.5k)· London

You'll use Java 17/21 with Spring, Maven, Groovy, JavaScript/TypeScript (Angular), Docker, GitLab CI/CD, IntelliJ, Windsurf, Splunk, and AppDynamics to build secure backend services, batches, and APIs for a global financial services company.

Work with Java, Python, JavaScript/TypeScript, Go, cloud platforms (AWS, Azure, GCP), CI/CD pipelines, and version control. Guiding the technical direction of BabuSpace’s premium short-term rental marketplace platform for African cities, designing backend architectures, and mentoring engineers.

Build enterprise-grade web applications using Python (Django/FastAPI), React, TypeScript, and PostgreSQL. Develop RESTful APIs, responsive UI components, and contribute to system design, CI/CD pipelines, and performance optimization.

You’ll work with Python (Django/FastAPI), React, TypeScript, PostgreSQL, REST APIs, and CI/CD. You’ll own end-to-end feature delivery on scalable, enterprise-grade web applications.

Build high-performance front ends with React, TypeScript, JavaScript, React Hooks, and ES6/ES7 for a leading HFT firm in London. The role focuses on UI engineering within a trading environment.

Java and Spring Boot, React, AWS, and CI/CD pipelines are the primary technologies. You will build microservices-based customer-facing applications for a leading retail bank’s cloud-native digital banking platform. No team size is stated.

Design, build and deploy production Generative AI applications, LLM-powered solutions and agentic frameworks using Python, LangChain, LangGraph, and OpenShift. You will automate enterprise workflows with intelligent agents, working with PostgreSQL and pgvector as part of Citi’s COO-Technology team building scalable AI for global operations. This is an Individual Contributor Staff Engineer role.

Deloitte★3.9 (14k)· London

You will use Figma, React, TypeScript, and HTML/CSS to design and front-end code AI-powered agentic experiences, including conversational interfaces and agent-orchestration workflows for clients. The team reimagines how users interact with intelligent platforms, developing trust-centered, multi-step AI interactions. You will manage design workstreams and mentor junior designers and front-end developers.

You'll work with FastAPI, TypeScript, React, OpenAI/Anthropic, PostgreSQL, and Azure to build AI agent systems—from voice interfaces to workflow orchestration—for aircraft maintenance and manufacturing. Fleetcraft builds infrastructure that helps technicians maintain and manufacture aircraft.

You will build and maintain Python services using FastAPI and Azure Functions, design and consume REST APIs, work with MS SQL Server, and leverage Azure infrastructure. The team delivers a loan management platform for a global financial services firm, handling complex servicing workflows in a regulated environment.

Edited★2.7 (3)· London

You will work with Python, *nix, LLMs, MCP, Django, Flask, FastAPI, Elasticsearch, and SQL databases. You will build an AI chatbot with agents and tooling, and scale a large-scale retail data infrastructure on AWS and bare metal for the company's AI-driven retail intelligence platform.

You'll work with FastAPI, Pydantic, TypeScript, React, OpenAI/Anthropic, PostgreSQL, Turbopuffer, Promptfoo, and Azure. The team builds AI agent systems and core infrastructure for aircraft maintenance and manufacturing, from voice interfaces to workflow orchestration.

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.

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.

DeepL★3.8 (4)· London

You will work with C#, Python, and JavaScript to build full-stack features on the Media Translation team, which develops DeepL’s core translation products—including the consumer web translator, Enterprise Customization Hub, and multimedia localization flows.

You'll work with Python and/or TypeScript, using full-stack JavaScript or backend Python. The role is a founding engineer at a stealth AI company backed by a £100M bootstrapped founder with three successful exits.

Checkout.com★3.8 (15)· London

You'll work with REST/JSON APIs, Postman, JavaScript, React, Angular, Java, .NET, Python, Node, and payment technologies like 3DS, tokenisation, and Apple/Google Pay. As a Sales Engineer, you'll support clients integrating Checkout.com's online payments platform, which powers transactions for companies like eBay, Uber, and Spotify.

Palantir★3.9 (37)· London

As an intern at Palantir, you will write high-quality code for Palantir Gotham, Foundry, or Apollo using Java, Go, and TypeScript, along with open-source tools like Cassandra, Spark, Elasticsearch, React, and Redux. You will join a small product-development team building features for users in public and private sectors, such as research scientists and intelligence analysts.