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.

Lead the EMEA Solutions Engineering team for Wise Platform, working with REST APIs (RESTful design, OpenAPI, OAuth2) and microservices architecture. The team helps top-tier banks and tech companies integrate Wise’s international finance products via their public API, providing post-sale technical consulting. You will build and mentor a high-performing technical delivery team, defining goals aligned with Wise Platform’s objectives.

Work with TensorFlow or PyTorch, Python, and related computer vision/graphics libraries on neural network architectures (convolutional, recurrent, transformer, diffusion-based). The Visual Computing Group (VCG) researches and develops generative models for game rendering and live video streaming to advance state-of-the-art runtime efficiency, visual quality, and latency.

Lead a team of Data Scientists and ML Engineers building AI solutions for financial markets using LLMs, Generative AI, Deep Learning, Transformers, Agentic AI, Python, PyTorch, TensorFlow, Hugging Face, LangChain, Semantic Kernel, Azure AI Foundry, AWS AI Services, and MLOps/LLMOps practices.

You will build AI agents using Python, SQL, Docker, Kubernetes, AWS (RDS, EKS, S3), GitHub Actions, RAG pipelines, BM25, vector search, hybrid retrieval, and knowledge graphs. These agents interpret geopolitical and financial signals for Kharon, a company providing global security risk intelligence.

Lead a disputes team at Checkout.com, working with a .NET/C# back end, React/TypeScript front end, and Python for machine learning, alongside REST APIs, event-driven microservices, and SQL. The team builds tools and models to help merchants manage and win chargeback disputes at scale. You will oversee engineers across disciplines and seniority levels, driving predictable delivery and operational efficiency.

Work with Python, LLMs, RAG pipelines, vector databases, Hugging Face Transformers, LangChain, PyTorch, and Docker to build production AI systems. Design, develop, and deploy AI-powered solutions such as conversational AI, document intelligence, and backend services for the Global Analytics team.

Build features across a dual-stack backend (TypeScript, C#, .NET) and microfrontend React apps, using AWS (ECS, Lambda, SQS, DynamoDB, DocumentDB), Terraform, SST, and AI coding agents. You'll evolve a B2B SaaS platform that powers UK housing transactions, adding new AI capabilities alongside a mature .NET foundation.

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.

You'll use Java, Kafka, Flink, SingleStore, HDFS/S3, and Scala to build high-performance, low-latency data systems. The Data Platform team in Global Markets owns the post-trade stack, processing high volumes of data and developing an AI-powered analytics UI/agent framework.

Work with Azure (API Management, Logic Apps, Service Bus, Functions, Data Factory, Synapse), .NET/C#, PowerShell, SQL/NoSQL, and AI tools like GitHub Copilot. You will design and develop secure data integrations across the Azure middleware estate for the All England Lawn Tennis Club, which stages The Wimbledon Championships.

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.

Work with Java/Spring, React, JavaScript/TypeScript, CI/CD pipelines, and distributed systems. You'll join the Account Integrity team building a globally scalable fraud prevention engine to protect customer accounts and prevent financial crime using machine learning and real-time monitoring.

Senior Developer role working with C#, .NET 4 & 6, SQL Server, Azure cloud services, SignalR, RabbitMQ, Kafka, Azure Service Bus, and CI/CD via Azure DevOps in an Agile environment. The team delivers a complex SaaS product for a regulated financial marketplace, requiring experience in financial or trading software.

Develop C# .NET BI applications using Visual C#.NET, Oracle, and SQL Server. Support existing applications and environments for a Japanese banking group's BI IT department, including data analysis with T-SQL and PL/SQL. Troubleshoot systems on Windows Servers and databases, liaising with teams in London and New York.

Design, develop and support D365 solutions across Power Platform and Dataverse, using C#, JavaScript, Power Automate, Power BI, and Power Apps. The role supports a major transformation programme, enhancing business processes and driving Dynamics adoption across the organisation.

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.

Use object-oriented programming (Java or C#), Salesforce Lightning, Force.com, Apex, SOQL, JavaScript, Git, Jira, IntelliJ, CI/CD, and Salesforce REST APIs. Hackajob Ltd is a platform that connects developers with job opportunities. This Salesforce Developer role delivers complex business and technical requirements on the Force.com platform.

You will work with .NET and C# as a Senior Developer in a Commodities trading environment. The role involves building on experience with the full trade life-cycle for a successful Commodities Trading company.

Wise★3.5 (42)· London

Lead a growing Solutions Engineering team in EMEA, providing technical consulting and product guidance to top-tier banks integrating Wise’s international finance products via REST API. Work with RESTful design, OpenAPI, OAuth2, and microservice architecture to architect integrations and influence the product roadmap.

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.

Goldman Sachs★3.9 (2.3k)· London

Build a high-performance, low-latency data platform for post-trade processing using Java, Kafka, Flink, SingleStore, HDFS/S3, and Scala. You will own the full lifecycle of core systems, designing distributed computation and an AI-powered UI/agent framework to deliver intelligent analytics over large-scale business data.

Zoopla★3.9 (18)· London

A 12-month maternity cover role on a dual-stack C#, .NET, and TypeScript backend with React microfrontends, using AWS managed services (ECS/Fargate, Lambda, SQS, DynamoDB, DocumentDB) and Terraform/SST. You'll build B2B SaaS software for estate agents and home builders at Alto Software Group. Take end-to-end ownership of features from design to production, working with the product team and AI coding agents.