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.

State Street★3.4 (3k)· London

You'll use SQL, Shell scripting, Python, Ansible, and ITIL to automate operations and improve production reliability. As a Production Support Engineer at State Street, you will manage application onboarding, troubleshoot incidents, and drive self-healing and resiliency patterns for the company's institutional investment services platforms.

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.

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.

Vodafone★3.6 (3.2k)· London

Work with Elastic Stack, Python, Kubernetes, Terraform, Ansible, CI/CD, Git, and Linux on the Cyber Security/Prevent team, supporting security platforms and delivering hands-on automation engineering to improve reliability and resilience across Vodafone Group and local markets.

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.

You will work with Python, YAML, JSON, Ansible AAP, NDFC, NX-OS, VXLAN BGP-EVPN, vPC, Git, GitHub/GitLab, pyATS, and Genie. The role involves building CI/CD pipelines and automation workflows for Cisco data centers, implementing GitOps and IaC on a contract network engineering project.

Senior Full-Stack Engineer building new features and improving existing platforms using PHP (Symfony, Zend) and JavaScript (Vue.js, React, Nuxt, Next.js). You will write unit, integration, and end-to-end tests, and work with CI/CD pipelines, Ansible, Terraform, and cloud environments (AWS, Azure, Google Cloud).

NiCE★3.4 (30)· London

You'll work with Python, Go, Java, C#, Bash, PowerShell, AWS (EC2, ECS, Lambda, DynamoDB), CloudFormation, Terraform, Jenkins, GitLab CI/CD, CircleCI, Docker, Kubernetes, Prometheus, Grafana, ELK stack, Cloudwatch, and optionally Grafana Observability Suite, Splunk, Datadog, PagerDuty, Rundeck, Ansible, Puppet, Chef. As an individual contributor, you'll run production, improve reliability, and support multiple large distributed software applications for NiCE, a provider of customer experience, financial crime, and public safety software.

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.

Work with AWS, Kubernetes, Docker, Terraform, CloudFormation, Python, Go, Jenkins, GitLab CI/CD, Prometheus, and Grafana. You will run production environments, build and automate infrastructure, and improve reliability for NICE’s suite of distributed software solutions.

As a Backend Software Engineer, you'll use Go or Node.js to build and scale the company's core real-time messaging platform, working on low-latency Pub/Sub services and state synchronization in an AI-first engineering environment.

Work with Azure, Terraform, Ansible, PowerShell, C#, Azure DevOps, Kubernetes, and CI/CD for containerisation and infrastructure as code. You will join a growing cloud team within an unnamed client, building and managing cloud environments.

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.

Python (3.10+) and Go development, with JavaScript/TypeScript for frontend; using RabbitMQ, Kafka, PostgreSQL, Redis, OpenTelemetry, and Prometheus. You will build and maintain low-latency real-time data feeds and web scraping pipelines to expand access to liquidity providers for sports prediction models.

Java (JVM), Kafka, cloud infrastructure, containers and Kubernetes, Git, and DevOps tooling. You will build resilient integrations and automated test frameworks for LMEsmart, the LME’s Inter‑Office Trading platform that handles trade registration, lifecycle management and matching.

You'll work with PHP (Symfony, Zend), JavaScript, Vue.js, React, Nuxt, Next.js, Ansible, Terraform, AWS, Azure, Google Cloud, and CI/CD pipelines. Xcelirate builds high-traffic platforms used by thousands of users per minute.

Work with TypeScript, Python, Node.js, Playwright, Cypress, WebdriverIO, Docker, GitHub Actions/GitLab CI, bash, and Jira to build and maintain test automation frameworks and CI pipelines for Connected TV devices.

G-Research★3.6 (18)· London

You will build automation frameworks and tooling using Python, Ansible, Terraform, and Jinja2, integrating them into CI/CD pipelines. This hands-on role sits at the intersection of networking and software engineering, developing APIs and self-service tools to power large-scale compute and research environments at a quantitative finance firm.

Design and build production-grade ML systems using MCP servers, recommendation systems, RAG pipelines, LLMs, and foundation models with Python, TensorFlow, PyTorch, FastAPI, and LangChain. You will own the end-to-end AI lifecycle for a sales data platform, deploying models into batch/real-time environments to drive forecasting, segmentation, and early warning systems. This role focuses on embedding context-aware intelligence into decision-making tools for business stakeholders.

Work with Java (JVM), cloud infrastructure, Kafka, Git, React.js (bonus), Python (bonus), Docker, Kubernetes, and Ansible. You will engineer resilient integrations and workflows for LMEsmart, the LME’s Inter-Office Trading platform, and develop automated test tooling and framework development.

You'll use TypeScript, Python, Node.js, Playwright, Cypress, or WebdriverIO, plus Docker, GitHub Actions/GitLab CI, and bash. The Quality Engineering team builds test-automation frameworks and CI pipelines that run on real Connected TV devices, targeting global TV users.