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.

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

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.

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.

Principal C#/.NET engineer leading solution design and hands-on development using C#, .NET Core, MongoDB, SQL Server, Kafka/ActiveMQ, and OpenShift/Kubernetes. Mentors developers and directs engineering, applying SOLID, microservices, and contract-first API design within a regulated financial services environment.

You will work with Python, JavaScript, SQL, Kafka, AWS/Azure, PostgreSQL, SQL Server, ClickHouse, and MongoDB. The team designs and delivers real-time, high-performance trading systems for Energy & Commodities, integrating market data, risk, and front-to-back office workflows.

You will work with Java and SpringBoot microservices on Linux and OpenShift, building APIs and using build tools like Gradle, CI/CD, Git, and BitBucket/GitHub. As part of the Technology Application Strategy team, you will design and deploy cutting-edge developer tooling and productivity solutions for Citi’s global developer community.

Work with Java, GitHub Copilot, Devin.AI, Citi Squad, Stylus Workspaces (Gemini, OpenAI, Claude, Llama), Docker, Kubernetes, and CI/CD. Build high-performance, real-time FX risk management systems for a greenfield platform with a 10+ year strategic commitment. As a VP, lead end-to-end delivery and technical direction.

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.

You will work with Unix/Linux, JavaScript, a ticketing system, and networking infrastructure tools. As a Support Engineer on the Global Support Engineering team, you will resolve technical issues with ExtraHop's network detection and response (NDR) product and assist customers with hardware, firmware, and third-party integrations.

NatWest Group★3.7 (1.2k)· London

You'll work with Mainframe hardware (DASD, SAN/FICON, IBM z), automation scripting (Python/Shell), infrastructure as code, GDPS, and CI/CD pipelines. As part of NatWest Digital X, you'll engineer hardware solutions for the Mainframe environment, applying automation to improve products. This technical lead role guides a team but no team size is specified.

The role involves troubleshooting network infrastructure, hardware, firmware, and third-party integrations using a ticketing system and video/phone channels. Preferred technologies include Unix/Linux

Design, configure and manage Mainframe Hardware solutions including DASD, SAN/FICON connectivity, and network infrastructure, using automation scripting (Python or Shell). You will engineer infrastructure-as-code for the Mainframe environment at NatWest Digital X, supporting hardware migrations between IBM z Mainframes and GDPS architectures. This is a technical lead role.

Palantir★3.9 (37)· London

Interns contribute to shared infrastructure powering Palantir Foundry, Gotham, and Apollo, plus internal tools like Rubix and Mission Manager. Work spans backend, developer, frontend, or storage infrastructure using Java, C++, Python, TypeScript, or JavaScript, alongside Kubernetes, observability tools, and production PaaS.

Palantir★3.9 (37)· London

You’ll work with Java, C++, Python, TypeScript, JavaScript, Kubernetes, Cassandra, Chromium, and open-source tools. As a new-grad infrastructure engineer, you’ll contribute to the shared infrastructure behind Palantir Foundry, Gotham, and Apollo—platforms deployed at key public- and private-sector institutions—as well as to Rubix and Mission Manager for sensitive environments. Teams are small, focused on backend, developer, frontend, or storage infrastructure, or on production infrastructure including a Kubernetes-based PaaS, Apollo, and Signals.

Microsoft★4.2 (9k)· London

This role involves coding in C, C++, C#, Java, JavaScript, or Python, applying AI, LLM tooling, and CI/CD practices. Engineers join a cross-functional team of software engineers, data scientists, and designers to build production-ready, AI-powered solutions for strategic customers, owning end-to-end system design for cloud and AI workloads.

MAREX★3.2 (6)· London

You will work with C# .NET, JavaScript, TypeScript, React, Node.js, GraphQL, Docker, NoSQL/RDMS databases, and AWS cloud services (ECS/EKS, Lambda, S3, RDS, API Gateway). The team builds and maintains applications to strengthen the company’s market-making capabilities and improve operational efficiency across multiple asset classes and geographies.

This role develops generative AI applications using Java, Python, React or Angular, LangChain, LlamaIndex, Hugging Face, Docker, Kubernetes, and AWS, with tools like GitHub Copilot. You will build scalable, AI-powered solutions for Citi’s global finance operations.

You will work with Java 21, Kotlin, REST APIs, PostgreSQL, MongoDB, Couchbase, Kafka, Docker, Kubernetes, and CI/CD tools. As part of Citi’s Developer Enablement team, you'll build and automate the bank’s strategic release management platform (Release on Demand) and a greenfield SDLC automation initiative, both used by 30,000 internal engineers.

Senior Java developer working with Spring Boot, J2EE, RESTful APIs, Microservices, Kubernetes or OpenShift, Angular, JavaScript, Bootstrap, HTML5, CSS3, SQL, PL/SQL, JBoss or Oracle 10gAS, Git, Maven, Jenkins. You will design, develop and enhance enterprise BSS/OSS solutions, mentoring junior developers within an Agile team.

Python, React, JavaScript/TypeScript, AWS, CI/CD, and observability. Build AI-powered language learning and assessment products for a global EdTech platform, integrating LLMs into scalable cloud-native applications with chat/messaging features.

You will build RESTful microservices with Java, Spring Boot, React, JavaScript/TypeScript, HTML and CSS, design and integrate REST APIs, and use Git, Docker, and Docker Compose. You will work with AWS or Azure and CI/CD tools like GitLab CI, GitHub Actions, or Jenkins in an Agile environment. This role is for a Full Stack Engineer contributing to product development at 83zero.

The Infrastructure Reliability Engineering Lead will lead a team of specialist engineers, implementing reliability engineering practices across infrastructure platforms for LME industrial metals trading and clearing services. The role focuses on observability, resilience engineering, automation, operational readiness, and service reliability improvement.