senior java backend developer jobs in London

About ARQARQ is one of the fastest-growing fintechs in the world. Our mission is to redefine how people interact with money across borders, building the infrastructure to move value seamlessly. We’re still early in our journey, which means every person who joins shapes the future of our product, culture, and growth. If you’re excited by big challenges,...

A technology consulting firm in the City of London is seeking a Senior/Principal Java Developer specialized in low-latency systems for the financial services sector. The role involves developing high-performance Java applications, eliminating performance bottlenecks, and maintaining a flexible work schedule. Candidates should have expertise in JVM internals...

Role: We are looking for an experienced, highly motivated Python developer with expertise in building robust data pipelines, creating and manipulating DataFrames, and turning defined specifications into reliable, production grade scripts. The role centres on developing and orchestrating the data infrastructure behind a systematic research platform: document...

Citibank (Switzerland) AG in London/Global Tech is seeking a senior Java engineer to design and deliver high‑performance trading platform components. You will collaborate with Traders, Quants and PMs to translate business needs into scalable solutions for live markets.The role requires deep Java expertise, knowledge of low‑latency distributed systems,...

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 crosses through our network. We do business in 180+ countries operating at a scale few can match. From deploying advanced AI to helping shape global markets, we build systems that matter. Look to join a team...

(Mid/Senior/Staff) Backend Engineer – London Please note that the positions are based in London, United Kingdom — relocation and visa support is provided if required. THE BEST WORK OF YOUR CAREER Trade Republic is the largest savings platform in Europe — we operate in 18 countries, serving +10 million customers who trust us with over €150B in assets....

Our mission is to enable everyone to build wealth We reinvent how trading and investing work by creating exceptional products people love. That takes high standards, high velocity and engineers who own what they ship. Today, we serve over 6 million clients, with more than €38 billion in assets under management. At that scale, performance, reliability and...

Senior Frontend EngineerRemote (UK-based) | Full-TimeReactive Markets is the 2026 OTC Trading Platform of the Year( Risk.net ). Our network handles over $50 billion in daily trading volumes across FX, Equities, and Cryptocurrency, connecting 40+ of the world's leading liquidity providers. We build trading systems that operate at the edge of what's...

Job DescriptionBackend Software EngineerLocation: LondonDESCRIPTIONOur platform is the video platform built for live, social and mobile. The cloud-based platform removes the traditional complexities of professional video production and distribution.We work with the world’s largest broadcasters and rights holders including: Sky Sports, BT Sport, Eurosport,...

Join to apply for the Java Developer role at OLM SystemsJoin to apply for the Java Developer role at OLM Systems Locations: Teddington, Glasgow, or Newport (Hybrid) Salary: Up to £39,000 per annum, depending on experienceJoin OLM Systems, the UK’s leading provider of case management solutions for social care and community health. We build modern SaaS...

Senior Frontend EngineerRemote (UK-based) | Full-TimeReactive Markets is the 2026 OTC Trading Platform of the Year( Risk.net ). Our network handles over $50 billion in daily trading volumes across FX, Equities, and Cryptocurrency, connecting 40+ of the world's leading liquidity providers. We build trading systems that operate at the edge of what's...

Senior Python Developer - GenAI Salary:£60,000 - £70,000 plus benefits, perks and healthcare options Locations:London, Bristol, Manchester, Glasgow or Newcastle Job Type:Permanent | Hybrid / 2 days per week onsite | Occasional travel to client sites Requirements:SC eligibility & full right to work in the UK required (no sponsorship available)The...

About this roleWithin the Aladdin Product Group – Private Markets, we are hiring a Senior Software Engineer to work on our Private Markets application suite. The position is based with our London team and operates as part of a broader team distributed across several countries worldwide. This team works with other London based agile teams to build...

About Octopus Electroverse We’re making electric vehicle ownership as smart and as simple as possible, by building the giant, virtual charging platform of the future. In just five years, Octopus Electroverse has grown to become one of the largest eMobility players globally, with over 1,400,000 connected electric vehicle chargers and a customer ecosystem...

Who we are Helsing is a defence AI company. Our mission is to protect our democracies. We aim to achieve technological leadership, so that open societies can continue to make sovereign decisions and control their ethical standards.  As democracies, we believe we have a special responsibility to be thoughtful about the development and deployment of powerful...

Senior Python Developer / Software Engineer (FastAPI Azure) London / WFH to £110kAre you a backend focused Software Engineer with strong Python skills combined with technical / team leadership experience?You could be progressing your career in a senior, hands-on role at a fast growing, global Insurance Underwriting technology provider that focusses on...

Company DescriptionOverviewSpecialist role Developer x 4 Summary of the work Senior back-end developer with python backgroundLatest start date 18/07/2016Expected contract length 6 months with an option to extend quarter on quarter at the Authority's sole discretion.Region LondonOrganisation the work is for UK Trade & InvestmentJob...

Company DescriptionDepop is a peer-to-peer circular fashion marketplace where anyone can buy, sell and discover secondhand fashion. Our mission is simple: to make fashion circular by making secondhand as exciting and rewarding as buying new.Founded in 2011, Depop’s diverse community has helped move resale into the mainstream, where buying secondhand is no...

Morson Edge (Financial Services) in London is seeking a Senior Java Developer to join the post-trade engineering team on a contract basis. You will design and develop market data and reference data feeds, building robust Java/SpringBoot microservices and REST APIs.The role focuses on auditing and leveraging market data, with exposure to CI/CD pipelines, TDD,...

BACKEND DEVELOPER (PHP) Intro to Gophr On demand delivery has never been so in demand. E-commerce has seen 5 years worth of growth in the past 12 months, and online grocery has gone nuts, bananas and crackers. Then add into the mix ever tighter margins, and all-time-high customer expectations (thanks Prime) and you see why better, and faster and more...