Full-stack Java development on Linux/Unix, using AI coding tools like Claude Code, Windsurf, Devin, or GitHub Copilot. The role is for Ascendion, a technology services company.

Citi★3.9 (21k)· London

Work with Solidity, Web3J/Web3JS/Ethers.js/Viem, Java/Spring, Node.js, and blockchains such as Ethereum, Hyperledger Besu, Canton, and Solana, using Hardhat/Foundry/Truffle for testing. Contribute to Citi's Integrated Digital Assets Platform (CIDAP) building Web3 components for tokenization, smart contracts, and on-chain settlement.

Hudson River Trading★4.5 (2)· London

You will write and maintain critical trading infrastructure using C/C++ or Python on Linux, working closely with engineers who design trading algorithms in a fast-paced, real-time environment. The role is with Hudson River Trading, a firm that brings a scientific approach to trading financial products.

RELX Group★3.8 (133)· London

You will work with Java/J2EE, JavaScript, JSP, C/C++, HTML, XML, SQL, Windows, UNIX, and .Net. The team supports products for education electronic health records that introduce students to digital charting and prepare them for clinical documentation.

Elsevier★3.8 (769)· London

Work with Java/J2EE, JavaScript, JSP, C/C++, HTML, XML, SQL, Windows, UNIX, .Net, and various data storage subsystems. You'll develop complex software solutions supporting educational electronic health record products that prepare students for digital charting in clinical environments.

Python micro-services with RabbitMQ and OpenShift/Kubernetes, using SQL Server and Parquet. The London Commodities Risk Technology team builds a front-office distributed platform for trading and risk calculations on assets like oil, gas, power, and exotics, collaborating with traders and quants.

Work with C# on .Net Framework 4.5.2+ and .Net 5+, using NUnit, xUnit, REST, Kafka/RabbitMQ, Git, and Linux. You will build Citi’s next-generation Equities technology platform for execution, clearing, and margin processes.

Develop dashboards and reports using Power BI, SQL, NoSQL (MongoDB), Linux/Unix, modern cloud tools, and languages like C#, Python, or Java. You’ll join a hyper-scaling fintech start-up building a market-altering product.

Lead DevOps Engineer: work with AWS, Azure, GCP, Terraform, Linux/Unix, Python/Go/PowerShell/Nodejs/C#, and CI/CD tools (Octopus/TeamCity/Jenkins/Azure DevOps). Role is at a tech consultancy building and running cloud infrastructure, automating deployments with IaC, and managing a team of engineers.

Work with modern C++ (C++17/20, template metaprogramming), network programming, distributed computing, and Unix/Linux. You will design and build efficient code for the production trading and research system within a newly formed Low Latency Trading group at a systematic hedge fund.

Work on Python (or comparable language) with multiple programming languages, Unix systems, and database technologies. Partner with trading, research, and data teams to develop core analytics, build data analytics trading tools, and integrate data into models for the Commodities team of a market-leading global hedge fund.

Work with Terraform, Ansible, Kubernetes, Python, Bash, Go, Jenkins, GitHub Actions, Prometheus, and Grafana to build infrastructure automation platforms supporting python-based quantitative research and trading systems. Manage on-premises resources across Ubuntu and Windows Server environments.

Work with C++, Python, Unix, and git in a quant fund's crypto division. You will build and optimize trading strategies, research new protocols and data sources, and design and improve research and trading systems.

Build scalable distributed systems with Java (Spring/Spring Boot) and Python, using Kafka, MQ, XML, and CI/CD in Unix/Linux environments. This Risk Services team within CRISIL supports capital-markets risk data ingestion, processing, analytics, and reporting for Global Markets.

Working with Core Python, Pandas, NumPy, Flask/FastAPI/Django, SQL, and Unix/Linux, you will build backend applications and data processing pipelines for trading and risk management within an investment banking environment, supporting risk calculations, trade workflows, and reporting.

You'll build distributed backend services and microservices using Java (Spring/Spring Boot), Python, messaging frameworks like Kafka/MQ, and Unix/Linux, with CI/CD and containerization. The Role sits on the Risk Services team within Global Markets, designing scalable systems for risk data processing, analytics, and reporting workflows.

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.

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.

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

Amazon★3.5 (56k)· London

Develop generative AI and large models using Java, C++, Python, and Unix/Linux for Prime Video’s observability team, which combines log management, tracing, and AI-powered analytics to detect and diagnose issues at unprecedented speed.

Nuffield Health★3.2 (939)· London

You will work with Java 21, Spring Boot, Maven, RabbitMQ, Apache Camel, Git, GitHub Actions, Docker, Azure DevOps, Terraform, Ansible, and SQL databases. The Integration Squad designs, develops, and supports microservices and APIs for Nuffield Health's digital healthcare platforms, enabling secure connectivity across internal and third-party systems.

A full-stack or backend specialist will use C# and .NET Framework, SQL Server (T-SQL), RESTful APIs, Azure DevOps, and messaging queues (RabbitMQ, Kafka) to build secure integration pipelines and backend services. They will execute a critical integration programme for an international Wealth Management firm to connect core internal and third-party systems.

Senior Python Developer role building trading and risk platforms using Python, SQL, Pandas, NumPy, Flask/FastAPI/Django, PySpark, Unix/Linux shell scripting, and enterprise platforms like Quartz or SecDB. The team develops backend services, data pipelines, and risk applications for trade lifecycle, risk calculations, and regulatory reporting within investment banking.

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.