18 senior backend developer jobs found in London

About Synechron: Synechron is a leading digital transformation consulting firm dedicated to delivering innovative technology solutions within banking, financial services, and insurance. We thrive on engineering excellence, collaboration, and a passion for cutting-edge technologies. Job Location: London (Hybrid - 3 days in the office) About the role: We are seeking a highly experienced Senior Java Developer with over 10 years of hands-on Java development experience and extensive exposure to AI/ML-driven systems . The ideal candidate will design, build, and scale enterprise-grade applications while integrating modern AI capabilities such as machine learning models, generative AI, and intelligent automation into Back End systems. Key Responsibilities Design, develop, and maintain high-performance, scalable Java applications using modern frameworks. Architect and implement AI-enabled solutions , integrating ML/AI models into Java-based platforms....

Who Are We? Xcelirate develops technologically-advanced platforms which are accessed by thousands of users every minute! We are proud to offer a workplace where the sharpest developers come together to strategically plan and swiftly execute practices which see us maintain our existing market dominance and attain global expansion. We owe our success to our customers who have seen us grow across a decade, and our talented team who have made that growth possible!   What are we looking for? You're a principal-level engineer first. The tech lead title is almost incidental. It just means you're the person the team orbits around, because that's what happens naturally when you're the one who understands the system most deeply and keeps the clearest head under pressure. The 10% that's people management fits inside your engineering work, not alongside it. You hire, you steer, you unblock, but you do it the way a strong engineer does everything: with good...

About Synechron: Synechron is a leading digital transformation consulting firm dedicated to delivering innovative technology solutions within banking, financial services, and insurance. We thrive on engineering excellence, collaboration, and a passion for cutting-edge technologies. Job Location: London (Hybrid - 3 days in the office) About the role: We are seeking a highly experienced Senior Java Developer with over 10 years of hands-on Java development experience and extensive exposure to AI/ML-driven systems . The ideal candidate will design, build, and scale enterprise-grade applications while integrating modern AI capabilities such as machine learning models, generative AI, and intelligent automation into Back End systems. Key Responsibilities Design, develop, and maintain high-performance, scalable Java applications using modern frameworks. Architect and implement AI-enabled solutions , integrating ML/AI models into Java-based platforms....

Who Are We? Xcelirate develops technologically-advanced platforms which are accessed by thousands of users every minute! We are proud to offer a workplace where the sharpest developers come together to strategically plan and swiftly execute practices which see us maintain our existing market dominance and attain global expansion. We owe our success to our customers who have seen us grow across a decade, and our talented team who have made that growth possible!   What are we looking for? You're a principal-level engineer first. The tech lead title is almost incidental. It just means you're the person the team orbits around, because that's what happens naturally when you're the one who understands the system most deeply and keeps the clearest head under pressure. The 10% that's people management fits inside your engineering work, not alongside it. You hire, you steer, you unblock, but you do it the way a strong engineer does everything: with good...

About Synechron: Synechron is a leading digital transformation consulting firm dedicated to delivering innovative technology solutions within banking, financial services, and insurance. We thrive on engineering excellence, collaboration, and a passion for cutting-edge technologies. Job Location: London (Hybrid - 3 days in the office) About the role: We are seeking a highly experienced Senior Java Developer with over 10 years of hands-on Java development experience and extensive exposure to AI/ML-driven systems . The ideal candidate will design, build, and scale enterprise-grade applications while integrating modern AI capabilities such as machine learning models, generative AI, and intelligent automation into Back End systems. Key Responsibilities Design, develop, and maintain high-performance, scalable Java applications using modern frameworks. Architect and implement AI-enabled solutions , integrating ML/AI models into Java-based platforms....

Who Are We? Xcelirate develops technologically-advanced platforms which are accessed by thousands of users every minute! We are proud to offer a workplace where the sharpest developers come together to strategically plan and swiftly execute practices which see us maintain our existing market dominance and attain global expansion. We owe our success to our customers who have seen us grow across a decade, and our talented team who have made that growth possible!   What are we looking for? You're a principal-level engineer first. The tech lead title is almost incidental. It just means you're the person the team orbits around, because that's what happens naturally when you're the one who understands the system most deeply and keeps the clearest head under pressure. The 10% that's people management fits inside your engineering work, not alongside it. You hire, you steer, you unblock, but you do it the way a strong engineer does everything: with good...

Job Title: Full Stack Developer (Java, Spring, React) - contract Location: London Hybrid. Travel to the London office on 3 days a week Duration: 11 months Contract Start Date: ASAP *note client onboarding takes 6 weeks from offer Day Rate: Competitive (Inside IR35)   Deloitte Working with the Deloitte Associate (Contractor) Programme means we can offer you the opportunity to work on a variation of industry and client related projects. Our aim is to retain the best talent and so when your project end date nears our team of Talent Community Advisors will be working with you to look at alternative projects within the firm that suit your experience should you wish to continue with Deloitte.   The Role We are looking for an experienced Full Stack Developers to work in the Technology and Transformation Team at Deloitte. You will work with one of our global financial services clients. This position requires an...

We are looking for Senior Java Developers to join on a contract basis (Inside IR35) . The ideal candidate will have experience building scalable microservices, working with event-driven systems, and deploying applications using containerized and cloud technologies. You will contribute to developing reliable backend services and help modernize legacy systems into cloud-ready architectures. Key Skills & Responsibilities Strong experience with Java (latest versions) and Spring Boot Experience designing and developing Microservices architectures Solid understanding of backend design patterns and best practices Experience working with SQL databases, particularly PostgreSQL Knowledge of Object-Oriented programming principles (OCP) Experience with event streaming platforms such as Kafka or RabbitMQ Hands-on experience with Docker and Kubernetes Experience working with AWS or other cloud platforms Ability to build scalable, reliable, and...

The CPS prosecutes criminal cases that have been investigated by the police and other investigative organisations in England and Wales. The CPS is independent, and they make their decisions independently of the police and government.   The primary focus of this role is about building capability and foundations, not delivering features.   We're looking for a highly experienced backend .NET developer who wants to use their expertise to support shaping software development in CPS and to grow our first cohort of in house back-end developers.   What the role is really about   There are two core priorities:   1.Mentoring and developing four backend apprentice developers. 2.Reviewing standard in place across teams to refine and document CPS software development standards.   At the moment, CPS relies almost entirely on suppliers for software development. We have very limited permanent, hands-on coding capability in...

Senior Software Engineer – Java (Contractor) Outside IR35 Rate: £400 - £500 per day Duration: 3 Months Plus Start Date: ASAP   As a Senior Software Engineer (Java) – Contractor at Pulselive, you’ll be focused on delivering robust, high-performance backend services and APIs that power digital experiences for millions of sports fans globally. This role is ideal for an experienced, hands-on engineer with strong Java and Spring expertise who thrives in a collaborative and fast-paced delivery environment. You’ll work closely with cross-functional teams to build, integrate, and optimize systems that handle real-time sports data, video, and live commentary. This position is project- and delivery-focused, with no line management or people-leadership responsibilities required.   Key Responsibilities: Design and develop scalable backend systems using Java and Spring Boot...

Python Platform Engineer (Contract) We tackle the most complex problems in quantitative finance, by bringing scientific clarity to financial complexity.   From our London HQ, we unite world-class researchers and engineers in an environment that values deep exploration and methodical execution - because the best ideas take time to evolve.  Together we’re building a world-class platform to amplify our teams’ most powerful ideas.   As part of our engineering team, you’ll shape the platforms and tools that drive high-impact research - designing systems that scale, accelerate discovery and support innovation across the firm.   Take the next step in your career.   The role The Storage Engineering team manages hundreds of petabytes across VAST, PowerScale, ECS, Rubrik, Alletra, Pure and a custom Tier Zero platform. The current operational tooling is a patchwork of GitOps workflows and Jenkins pipelines. We're...

  About Us We manage some of the UK’s largest and most complex wireless environments, including multiple central London boroughs and Docklands. Across more than 5,000 mast site locations, 2,000 connected buildings and 200+ outdoor networks, our work helps ensure people stay connected where it matters most. Backed by DigitalBridge, we bring together deep telecoms expertise and commercial real estate know-how to deliver long-term impact in the market. We are also proud to be certified as a Great Place to Work , with 82 percent of our people saying it is a great place to work, compared with 54 percent at a typical UK-based company.   The Role At Freshwave , we are looking for an experienced Senior Project Manager to join our delivery team on an initial 6-month day rate contract , with strong potential for extension. This is an exciting opportunity to take ownership of complex indoor mobile and WiFi deployment projects , playing a...

275-300 Outside IR 35 City London Province Greater London Country United Kingdom Postal Code EC1A Job Description About Scrumconnect Consulting Scrumconnect Consulting is a multi-award-winning digital consultancy, recognised for delivering impactful technology solutions across UK government departments. Our work has positively influenced the lives of over 40 million UK citizens. With a strong commitment to user-centred design and agile delivery, and more to deliver innovative digital services that matter.   Role Overview We are looking for a Senior Performance Tester with Active SC to deliver hands-on load and performance testing across large-scale digital services and backend applications, with experience of working with cloud-based distributed services. This is a technical, delivery-focused role operating in structured and governed environments where performance, resilience, and...

We are looking for Senior Java Developers to join on a contract basis (Inside IR35) . The ideal candidate will have experience building scalable microservices, working with event-driven systems, and deploying applications using containerized and cloud technologies. You will contribute to developing reliable backend services and help modernize legacy systems into cloud-ready architectures. Key Skills & Responsibilities Strong experience with Java (latest versions) and Spring Boot Experience designing and developing Microservices architectures Solid understanding of backend design patterns and best practices Experience working with SQL databases, particularly PostgreSQL Knowledge of Object-Oriented programming principles (OCP) Experience with event streaming platforms such as Kafka or RabbitMQ Hands-on experience with Docker and Kubernetes Experience working with AWS or other cloud platforms Ability to build scalable, reliable, and...

  About Us We manage some of the UK’s largest and most complex wireless environments, including multiple central London boroughs and Docklands. Across more than 5,000 mast site locations, 2,000 connected buildings and 200+ outdoor networks, our work helps ensure people stay connected where it matters most. Backed by DigitalBridge, we bring together deep telecoms expertise and commercial real estate know-how to deliver long-term impact in the market. We are also proud to be certified as a Great Place to Work , with 82 percent of our people saying it is a great place to work, compared with 54 percent at a typical UK-based company.   The Role At Freshwave , we are looking for an experienced Senior Project Manager to join our delivery team on an initial 6-month day rate contract , with strong potential for extension. This is an exciting opportunity to take ownership of complex indoor mobile and WiFi deployment projects , playing a...

Must have skills: Demonstrable experience with Solidity. Strong understanding of blockchain security practices and potential vulnerabilities. Proficiency in Hardhat and Foundry. Experience with Solidity security testing tools like Slither, Mythril, Echidna Practical experience with scripting languages like Javascript or Typescript. Ability to craft unit, integration, fork, and invariant tests, ensuring code longevity. Demonstrable aptitude for best development practices, data structures, algorithms, and methodologies. Bachelor's degree in Computer Science, Engineering, or a related STEM discipline. Excellent debugging and troubleshooting skills. Strong written and verbal communication skills. Self-motivated with the ability to work in a fast-paced, evolving environment. Proficient communication skills in English. Development background in sectors such as banking, finance, or trading, paired with a comprehensive grasp of financial...

275-300 Outside IR 35 City London Province Greater London Country United Kingdom Postal Code EC1A Job Description About Scrumconnect Consulting Scrumconnect Consulting is a multi-award-winning digital consultancy, recognised for delivering impactful technology solutions across UK government departments. Our work has positively influenced the lives of over 40 million UK citizens. With a strong commitment to user-centred design and agile delivery, and more to deliver innovative digital services that matter.   Role Overview We are looking for a Senior Performance Tester with Active SC to deliver hands-on load and performance testing across large-scale digital services and backend applications, with experience of working with cloud-based distributed services. This is a technical, delivery-focused role operating in structured and governed environments where performance, resilience, and...

We are looking for Senior Java Developers to join on a contract basis (Inside IR35) . The ideal candidate will have experience building scalable microservices, working with event-driven systems, and deploying applications using containerized and cloud technologies. You will contribute to developing reliable backend services and help modernize legacy systems into cloud-ready architectures. Key Skills & Responsibilities Strong experience with Java (latest versions) and Spring Boot Experience designing and developing Microservices architectures Solid understanding of backend design patterns and best practices Experience working with SQL databases, particularly PostgreSQL Knowledge of Object-Oriented programming principles (OCP) Experience with event streaming platforms such as Kafka or RabbitMQ Hands-on experience with Docker and Kubernetes Experience working with AWS or other cloud platforms Ability to build scalable, reliable, and...