Senior Software Engineer will work with Java 25, Spring Boot, PostgreSQL, REST APIs, and microservices, using TDD, DDD, and CI/CD. They will build and maintain backend systems for a fintech focused on cross-border money movement, including card payments, treasury, transactions, and crypto liquidity.

Lead Software Engineers at ARQ work with Java 25, Spring Boot, Postgres, TDD, DDD, and CI/CD to build REST APIs and microservices. The team develops fintech systems powering card payments, treasury management, transaction booking, and crypto liquidity.

Work with Java 25, Spring Boot, Postgres, and CI/CD practices building REST APIs and microservices. The team develops backend systems for fintech products including card payments, treasury management, and crypto liquidity.

Citi★3.9 (21k)· London

Build index‑calculation platform components at Citi using Scala and Python, integrating via REST APIs and Solace message queues, and working with Couchbase (NoSQL), Gradle, Jenkins, Tekton, and OpenShift. The SolstiCE team supports the Citi Investment Strategies (CIS) engineering group by developing and maintaining an index calculation platform for the Equity Derivatives Tech business.

Develop core eTrading MI & Analytics platform components using q and kdb+, with CI/CD, TDD/BDD, and an additional programming language. The platform captures, stores, and analyses over 3TB/5 billion daily records from electronic trading venues for risk, quant, trading, and sales stakeholders.

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.

Develop low-latency server-side Java components for a global eTrading and eRisk platform serving FX and electronic execution. You’ll work with enterprise messaging (multicast, low-latency), FIX protocol, kdb+, and apply CI, TDD/BDD. The team builds distributed systems for pricing, order execution, and algorithmic trading.

Java back-end developer using microservices, REST APIs, AWS (Lambda, EKS, RDS, S3, MSK), CI/CD, and AI tools (GitHub Copilot, LLMs). Builds next-gen trading and cash management systems for the Short-Term, Cash, and Collateral desks, modernizing platforms and migrating to AWS.

Java 11+, Spring Boot, microservices, event-driven architecture, Terraform, and cloud platforms (Azure, AWS, or GCP). The team builds post-trade technology solutions including business-critical applications, APIs, client reporting platforms, and web portals for capital markets. You will mentor developers and contribute to architectural decisions.

Java (JDK 11+), multithreading, SQL/NoSQL databases (Oracle, MySQL, PostgreSQL, MongoDB, Cassandra), message queuing (Kafka, Tibco, Solace), Linux, JVM, and TDD. This tech lead role builds high-performance FX risk calculation systems for Citi’s Markets technology team, which supports global trading and risk management.

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.

Cboe Global Markets★3.7 (14)· London

You'll work primarily with Python to design and build highly reliable trading systems, working closely with advanced SQL, Linux, and optionally PostgreSQL, Snowflake, Apache Kafka, Apache Airflow, Django, Flask, or FastAPI. You'll expand data pipeline and event streaming functionality for Europe's largest equities exchange and related platforms, while leading complex projects, mentoring developers across multiple global teams, and participating in production support for Cboe Europe's trading operations.

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).

Atos★3.5 (3.2k)· London

You will work with **Java, Spring Boot, React JS, AWS Cloud, Microservices, Mulesoft (Anypoint Studio, API Manager), CI/CD, Git, and Jest**. The team supports, enhances, and modernizes complex enterprise applications as part of large-scale digital transformation and cloud migration programs at Atos, a global digital services provider.

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.

Infosys★3.8 (17k)· London

You will work with Java, Spring Boot, Hibernate, JPA, React/Angular/Vue.js, HTML5, CSS3, JavaScript, RESTful APIs, SQL/NoSQL databases, Git, and CI/CD tools on cloud platforms (AWS, Azure, GCP). As a Senior Consultant at Infosys, a global digital services and consulting firm, you'll contribute across the consulting lifecycle—defining problems, proposing solutions, and guiding development, configuration, and deployment while mentoring teams and shaping client-focused solutions. Docker and Kubernetes experience is a plus.

You'll work with Java 7/8+, Spring framework, Angular/React, REST, Hibernate, Docker, Terraform, GitHub, Jenkins, and cloud platforms (Azure/AWS). Solirius Reply is a technical consultancy that embeds consultants with clients across public and private sectors to deliver application delivery and solve real-world technical problems, with exposure to diverse projects.

You will lead a small cross-functional data pod building data pipelines, models and services in Python, SQL and Snowflake to turn supply chain data into customer-facing sustainability insights. The role combines hands-on data engineering with technical leadership and line management of the pod's engineers.

You will work with Java, Spring Boot, React JS, JSF UI, AWS, Microservices, Mulesoft (Anypoint Studio, API Manager), CI/CD, Git and Jest. The team supports, enhances and modernizes complex enterprise applications and large-scale digital transformation initiatives for the company's global clients.

You will work with Python, Java, TypeScript/JavaScript, SQL, AI SDKs, and cloud platforms (AWS, Azure, GCP) to build LLM orchestration, RAG, MCP, and agentic AI patterns. As technical

Senior Frontend Engineer role at Pracyva ltd using React, TypeScript, JestJS, and axe-core. The engineer will build accessible, testable, scalable UIs with a test-first approach and coach peers.

This role involves Django, NHS Front End Toolkit, GDS, CI/CD, IaC, TDD/BDD, and pair/mob programming. You will work in multi-disciplinary, user-centred design teams delivering accessible front-end applications for the UK public sector, with experience in AI-augmented front-end, Python, API integration, and legacy system modernisation valued.

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.

You will design and build data pipelines, models, and services in Python and SQL, using Snowflake for warehousing. You will lead a small cross-functional data pod that transforms supply chain data into customer-facing insights for Sedex’s SaaS sustainability platform. This role includes line management of the pod’s engineers.

You will work with Go, cloud environments (AWS, Azure, Google Cloud), APIs, backend services, Docker, Kubernetes, and TDD. As a Senior Software Engineer at YLD, you’ll join a client team building innovative products as part of a remote-first consultancy.