Java Developer Jobs in London, UK

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview About Citi As the world's most global bank, Citi gives you the tools to be a trailblazer. We're not just building technology; we're building the future o...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview FX Risk Java Tech Lead Engineer the future of global finance. At Citi, our Tech team doesn't just support finance - we are helping to redefine it. Every ...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview Engineer the future of global finance. At Citi, our Tech team doesn't just support finance - we are helping to redefine it. Every day, $5 trillion crosse...

Hays are now looking for a Java Developer on a 12 month contract. The client requires all candidates to already hold SC Clearance and NPPV3. 428 Inside IR35 Mainly Remote (once a month in Bridgend or Reading) Candidates must hold current NPPV3 & SC Clearance 12 month contract Our client is building a team to support and maintain a critical national policing system used across the UK. This role focuses on Level 3 support, troubleshooting, and...

Java Developer - Active SC, Java, Oracle WebLogic Up to 425 per day (Inside IR35) Remote 12 months My client is an instantly recognisable Consultancy who are hiring a Java Developer with Active SC Clearance (Security Cleared), Java, Oracle WebLogic and ElasticSearch skills to work with a high profile end client. Key Requirements: Demonstrable experience as a Java Developer Active SC Clearance is essential; NPPV3 would be advantageous Strong expe...

Java Developer – Front Office / Trading Systems Join MARGO in the UK (London) – Perm & Contracting Opportunity*   MARGO is a tech-native consultancy delivering high value-added IT expertise to the financial services industry. We specialise in complex software engineering environments where performance, robustness and scalability are critical: low latency systems, real-time data processing, distributed architectures and high-volume flows. Joining MARGO means working in demanding Front Office and Risk IT environments, while benefiting from a human-sized structure, close follow-up and tailor-made training paths. Business Context You will join the Front Office / Trading IT environment of one of our tier-1 investment banking partners. The teams design and maintain mission-critical Java systems supporting electronic trading activities across multiple asset classes (e.g. Equities, Fixed Income, Commodities, FX, Derivatives). The environment is characterised by: ·        Real-time and event-driven architectures ·        High performance and low-latency constraints ·        Close interaction with trading, quantitative and risk teams ·        Short delivery cycles and high engineering standards Role Overview We are looking for an experienced Java Developer to work on real-time trading and risk systems. The role is primarily technical, focused on software engineering excellence rather than business analysis. Candidates are expected to have prior exposure to Front Office, Trading or Risk environments, regardless of the underlying asset class. Key Responsibilities Design & Development ·        Design, develop and maintain high-performance Java applications ·        Work on real-time data processing (market data, pricing, orders, analytics) ·        Implement multithreading and concurrency patterns adapted to performance-critical systems ·        Participate in system design, architecture discussions and technical specifications ·        Continuously optimise performance (latency, throughput, memory, GC behaviour) Engineering & Delivery ·        Contribute to the full software lifecycle: design, development, testing and release ·        Produce clean, maintainable and well-tested code ·        Participate in sprint planning, estimations and technical reviews ·        Collaborate closely with developers, quant and infrastructure teams Production & Support ·        Provide 3rd line support on production systems when required ·        Participate in production releases (including occasional out-of-hours interventions) ·        Contribute to system stability, monitoring and incident prevention Technical Environment Core Technologies ·          Java (expert level)      - Multithreading & concurrency     - Performance optimisation & low latency techniques    -  Garbage Collection awareness ·          Linux / UNIX environments ·          Distributed systems and messaging architectures ·        Performance monitoring and profiling tools Valued Technical Exposure ·        Event-driven or real-time systems ·        Messaging middleware (Kafka, Solace or equivalent) ·        FIX or other market connectivity protocols ·        Networking fundamentals (TCP/IP, multicast) Required Experience & Skills Essential ·        Strong experience as a Java Developer in performance-critical environments ·        Proven background in low-latency or high-throughput systems ·        Solid understanding of concurrency, threading and memory management ·        Experience working in Front Office, Trading or Risk IT environments ·        Comfortable working in Linux production environments ·        Clear communication and structured problem-solving skills Valued (but not restrictive) ·        Exposure to one or more asset classes (Equities, Fixed Income, Commodities, FX, Derivatives) ·        Experience in trading, pricing, risk or market data systems Why Join MARGO ·        Access to multi-asset Front Office environments ·        Highly technical and challenging engineering assignments ·        Strong emphasis on skill development and long-term career progression ·        Human-sized consultancy with close support and high-quality missions   Please note - We do not offer visa sponsorship for this position. Interested? Motivated? Apply on our website or at staff.uk@margo.com

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview About Citi As the world's most global bank, Citi gives you the tools to be a trailblazer. We're not just building technology; we're building the future o...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview About Citi As the world's most global bank, Citi gives you the tools to be a trailblazer. We're not just building technology; we're building the future o...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview FX Risk Java Tech Lead Engineer the future of global finance. At Citi, our Tech team doesn't just support finance - we are helping to redefine it. Every ...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview Engineer the future of global finance. At Citi, our Tech team doesn't just support finance - we are helping to redefine it. Every day, $5 trillion crosse...

The exchange team develops and maintain a cutting-edge trading platform. With a global presence across APAC, EMEA and North America, the team has since grown with the goal to provide a seamless and secure trading experience for our clients.

Java Developer - Active SC, NPPV3, Java Up to 425 per day - Inside IR35 Primarily Remote 12 months My client is an instantly recognisable consultancy who require a Java Developer with Active SC and NPPV3 clearance for a client within the public sector. Key Requirements: Proven commercial experience working as a Java Developer within the Public Sector. Active SC and NPPV3 Clearance. Senior-level expertise in either Java/Spring (Boot, Data JPA, Se...

Job Role: Java Developer eTrading Location: London Hybrid Duration: until December 2026 Hybrid: 3 days onsite IR35 Status: Inside (PAYE) Start Date: ASAP Your role We are seeking an experienced candidate to join our eFX Quantitative Developer team within Global Markets This is a fast paced and collaborative team that are responsible for the development and enhancement of the best-in-class eFX platform The team sits within the Global Markets Prin...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview FX Risk Java Tech Lead Engineer the future of global finance. At Citi, our Tech team doesn't just support finance - we are helping to redefine it. Every ...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview Citi's Markets technology team is growing at lightning speed, and we're looking for talented technologists to help build the future of global banking. Ou...

Senior Java Backend Engineer (Distributed Systems & Messaging) Location: London, UK (Hybrid) Role Type: Permanent Tech Stack: Java 8+, Concurrency, Apache Kafka / JMS / TIBCO, Spring Boot, Microservices, Low-Latency About the Team & Platform We are building and scaling a complex, high-throughput, electronic trading platform distributed across several international hubs. Our development environment is structured around highly autonomous, ...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview Engineer the future of global finance. At Citi, our Tech team doesn't just support finance - we are helping to redefine it. Every day, $5 trillion crosse...

Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview About Citi As the world's most global bank, Citi gives you the tools to be a trailblazer. We're not just building technology; we're building the future o...

We are a leading global asset management firm with over 3,000 employees across 20 offices in 15 countries; we help millions of investors around the world pursue their financial goals. We hire critical thinkers. People who thrive in a collaborative culture like ours where we solve real problems while building the future of finance. You Are excited to be part of a vibrant engineering community that values diversity, hard work, and continuous learn...

We are a leading global asset management firm with over 3,000 employees across 20 offices in 15 countries; we help millions of investors around the world pursue their financial goals. We hire critical thinkers. People who thrive in a collaborative culture like ours where we solve real problems while building the future of finance. You Are excited to be part of a vibrant engineering community that values diversity, hard work, and continuous learn...