Top Java Developer Jobs in London

Design and build real-time liquidity observability infrastructure and high-throughput streaming data pipelines for global financial operations. Architect Kafka and Flink systems, implement reliable event processing, real-time aggregation, streaming data models, and sub-second analytical querying. Partner with product, data science, quantitative analysis, and treasury teams while addressing latency, resilience, regulatory, and financial trade-offs. Develop well-tested systems supporting liquidity attribution, cash positioning, transaction routing, and ML forecasting.

Design, develop, test, deploy, and maintain scalable Java applications, services, and platforms supporting investment and business workflows. Build distributed systems, APIs, data platforms, and event-driven architectures; modernize existing technology; improve performance, reliability, and scalability; and contribute to architecture and technical strategy. Partner with users and engineering teams throughout the software development lifecycle to deliver production-quality solutions.

Develops and supports secure, scalable Java and Spring Boot applications within an agile Payments Technology team. Responsibilities include software design, production coding, troubleshooting, architecture documentation, automated testing, CI/CD, system resiliency, and high-throughput distributed systems development. The role also uses and guides responsible AI-assisted software development, analyzes application data, improves coding practices, and supports operational stability.

Leads hands-on development of secure, scalable Java applications, APIs, and services for JPMorganChase’s International Private Bank. Designs complex solutions, writes and reviews production code, improves reliability and observability, and supports testing, migration, releases, and operations. Mentors engineers, guides AI-assisted engineering practices, collaborates with product and business teams, and translates financial workflows into dependable client-facing capabilities.

Design, build, and operate Wise’s Continuous Delivery platform using Java and Go. Extend Spinnaker, develop deployment guardrails and integrations, improve shared infrastructure, and support reliable large-scale software delivery. Responsibilities include distributed services, APIs, observability, failure handling, automation, technical design, code reviews, documentation, and collaboration with engineering teams. The role also contributes to platform operations, technical direction, and engineer development.

Develop secure, scalable backend and data solutions using Java, Python, Spring Boot, Databricks, Kafka, and cloud technologies. Responsibilities include designing microservices and event-driven architectures, integrating SQL and NoSQL databases, building data workflows, writing automated tests, reviewing code, troubleshooting production systems, and improving operational stability through automation. The role also contributes to agile practices, AI-assisted development, communities of practice, and enterprise software engineering standards.

Design and build scalable AML detection controls for money laundering and terrorist financing risks. Own major projects and technical roadmaps, influence product decisions, improve reliability, security, and technical quality, and mentor engineers. Work with Java, Spring Boot, Kafka, distributed services, asynchronous processing, and large-scale data alongside product, data science, analytics, and AML specialists.

Develop, test, and support reliable, high-performance distributed Java applications for real-time streaming and concurrent workloads. Partner with stakeholders, present and review designs, improve reliability/observability/performance, and support production releases to meet SLAs within BGM Data & Analytics.

Develop and operate highly available, scalable, low-latency Java components for a global macro e-trading platform. Responsibilities include system design, software development, testing, deployment, performance optimization, troubleshooting, and operational support. The role requires expertise in Linux/Unix, networking, middleware, FIX protocol, CI/CD, automated testing, secure software development, and responsible use of AI-assisted engineering tools. Collaboration with global developers and trading partners is central, with relevant FX or Rates e-trading experience preferred.

Owns the design, development, deployment, and support of software for corporate credit derivative trading. Partners with traders, strategists, operations, and global technology teams to deliver pricing, risk, distribution, automation, and platform improvements. Provides technical leadership, applies software engineering best practices, uses AI and agentic tools, and may manage developers and contractors. Requires strong object-oriented programming, multithreading, data structures, design patterns, and experience with Java or .NET; Scala and Python are preferred.

Develop and maintain Java-based automated testing frameworks using Selenium and RestAssured. Create UI, API, integration, regression, and end-to-end tests; support manual testing, defect investigation, test traceability, CI/CD execution, and shift-left quality practices. Collaborate with product, engineering, QA, and subject matter experts in an Agile environment to improve coverage, reliability, and delivery confidence for healthcare and genomic software systems.

Build and scale Wise’s recommendation platform, APIs, onboarding experiences, and reward mechanisms. Develop distributed systems and customer-facing product experiences while collaborating with product managers, data scientists, analysts, designers, and engineers. Own projects end to end, write testable code, apply best engineering practices, improve team processes, and use customer-focused, data-driven decisions to address pain points.

Develop and enhance FX electronic trading systems using Java and ultra-low-latency practices. Design system architecture, build new platforms, replace legacy systems, troubleshoot software and infrastructure issues, and collaborate with FX traders, quants, and technology teams. The role also contributes to engineering best practices, documentation, process consistency, and quality improvements while maintaining compliance with Citi policies.

Develop and support scalable, low-latency Java applications for cross-border FX payments and custody. Design architecture, build and test features, modernize legacy systems, improve development practices, and provide third-line production support. Collaborate with sales, trading, quants, product, and technology teams to deliver data-driven solutions. Mentor junior engineers and apply AI coding tools, messaging, databases, caching, cloud-native technologies, and CI/CD practices.

Develop and support cloud-native Java applications for cross-border FX payments and custody. Responsibilities include system architecture, feature development, testing, production support, lifecycle improvement, stakeholder collaboration, mentoring, and best-practice implementation. The role requires expertise in Java, Spring, SQL, messaging, caching, ultra-low-latency development, AI coding tools, and scalable production systems, with FX knowledge preferred.

Build and support scalable, performant Java applications for BlackRock Global Markets. Responsibilities include gathering requirements, designing architectures, developing and testing software, conducting code reviews, improving reliability and observability, supporting production releases, and driving SDLC improvements. The role requires collaboration with business stakeholders and distributed technology teams, with emphasis on microservices, event-driven systems, cloud platforms, DevOps, and high-volume or latency-sensitive workloads.

Develop and maintain scalable Java applications using Java SE, Java EE, Spring Boot, Hibernate, and Struts. Build RESTful API integrations, write clean and tested code, troubleshoot defects, participate in code reviews, optimize performance, and maintain documentation. Collaborate with engineers, architects, product teams, and other stakeholders in an agile environment. The role may also involve microservices, cloud platforms, and frontend technologies.

Design and deliver enterprise-grade web application platforms for Citi’s capital management transformation. Build Java and Spring Boot microservices with MongoDB and Microsoft SQL Server data layers, develop REST and GraphQL APIs, and apply strong testing, SDLC, CI/CD, security, and production-readiness practices. Lead technical design discussions, collaborate with global product and engineering teams, use AI coding tools, and take end-to-end ownership of reliable software delivery in an Agile environment.

Lead development of enterprise-grade capital management platforms using Java, Spring Boot, microservices, MongoDB, and Microsoft SQL Server. Own architecture, API-first development, testing, CI/CD, security compliance, and production readiness. Collaborate with product and engineering teams in an Agile global squad, leverage AI coding tools, and lead technical design discussions.

Develop and enhance FX trading systems using Java and ultra-low-latency practices. Design system architecture, build new platforms, modernize legacy systems, troubleshoot technical issues, and collaborate with FX traders, quantitative teams, end users, and technology teams. The role also involves codebase analysis, implementation of engineering best practices, maintaining documentation, and ensuring compliance with Citi policies and procedures.

Lead development of cloud-hosted, JVM-based applications supporting equity derivatives trading and pricing. Mentor developers, establish engineering and AI best practices, translate trading and business requirements into technical designs, and deliver reliable backend services. Improve scalability, performance, observability, and SDLC quality while collaborating with traders, quants, and technology teams. The role involves Java/Kotlin engineering, distributed systems, containers, CI/CD, cloud deployment, and derivatives-market technology.

Leads development and operation of secure, high-performance Java trading systems. Designs latency-sensitive distributed services, APIs, integration strategies, resiliency, observability, and automation. Oversees architecture, coding, testing, incident response, production stability, and SDLC security. Guides AI-assisted engineering practices, mentors developers, and coordinates technical planning and delivery across globally distributed teams.

Lead development of cloud-hosted Java and Kotlin applications supporting equity derivatives trading, pricing, and market data. Mentor developers, establish engineering and AI development practices, translate trading and quant requirements into technical designs, and improve system performance, scalability, reliability, and observability. Collaborate with traders, quants, and technology teams while modernizing platforms through containers, microservices, CI/CD, and DevOps practices.

The Java Software Engineer will develop robust and scalable code for customer services using Java, AWS, and Postgres, while advocating for clean coding and best practices.

Develop and lead ultra-low-latency Java and Rust systems for algorithmic trading within Citi’s High Performance Architectures team. Build event-sourced microservices, market data replay and backtesting utilities achieving 10–100 microsecond response times. Define architectures, tune performance, integrate new products, analyze complex systems, and mentor engineers. Collaborate with senior leaders and end users while supporting modernization across global Markets Technology teams.