42 senior software engineer jobs found in London

Joining a new project Ideally have worked on Financial Services Projects before (Payments would be great) Emphasis on Architecture over Development (Must have a solid Development Background) Must be comfortable sitting in client meetings and advising Start date ASAP Duration 3 months (Likely to extend) 3 days / week in person working (London) Immediate Interviews   The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages.   Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We've been consistently profitable and have grown responsibly from the beginning.   We are based at Old Street in the heart of "tech city"...

Joining a new project Ideally have worked on Financial Services Projects before (Payments would be great) Emphasis on Architecture over Development (Must have a solid Development Background) Must be comfortable sitting in client meetings and advising Start date ASAP Duration 3 months (Likely to extend) 3 days / week in person working (London) Immediate Interviews   The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages.   Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We've been consistently profitable and have grown responsibly from the beginning.   We are based at Old Street in the heart of "tech city"...

Join Secure Code Warrior to create a safer digital landscape by assisting companies to secure their software through developer-led practices!   Secure Code Warrior’s mission is to establish new standards for coding that transform the ways software is created. We do this by providing the world’s leading agile learning platform that delivers the most effective secure coding solution for developers to learn, apply, and retain software security principles. More than 600 enterprises trust Secure Code Warrior to implement agile learning security programs, build safer software, and create a culture of developer-driven security. We are a venture-backed company with offices in Australia, the United States, Belgium, Iceland, and the United Kingdom.   Secure Code Warrior is seeking a Senior Engineer to take long-term ownership of our core system-level product suite across Windows and macOS. In this contract role, you will be the architectural...

🚀 Senior DevSecOps Engineer – Contract Opportunity (Inside IR35) UK GOVT CONTRACT - 6 months   Fimatix UK Ltd is looking for a Senior DevSecOps Engineer (SFIA 7) to join our team and play a key role in building and securing modern DevSecOps capabilities across a large-scale digital programme. This is a hands-on engineering role focused on embedding secure-by-design practices into CI/CD pipelines, AWS infrastructure, and identity services , while also helping drive AI-enabled DevOps automation to improve operational intelligence and threat detection.   🔧 Key Responsibilities Design and implement secure CI/CD pipelines with integrated security tooling (SAST, DAST, container scanning, dependency scanning). Embed security-by-design principles across AWS infrastructure and deployments. Implement IaC security guardrails using Terraform/CloudFormation. Configure and optimise AWS-native security services (Security Hub,...

Senior Software Deployment Engineer - Contract - Ouside IR35 Mindera are currently looking for a Senior Software Deployment Engineer who can lead the delivery, configuration, testing, and rollout of applications and retail device solutions across complex, large-scale environments. In this role you will help shape deployment strategy, drive automation, improve reliability, mentor engineers, and work closely with product, platform, and engineering teams to ensure smooth, secure, and high-quality releases that reaches thousands of customers. This is a hybrid role and you will be expected to be on site in Bracknell 3 days per week. Requirements Deployment & Configuration Leadership Lead end-to-end deployment processes across Dev, Test, UAT, Pre-Prod, and Production. Design scalable, repeatable deployment workflows and environment strategies. Drive automation across CI/CD pipelines using scripting, IaC, and tooling improvements. Ensure...

Description We are seeking a passionate Software Engineering Manager with a strong background in modern frontend engineering, particularly React, Next.js, and TypeScript, to provide technical leadership and operate with excellence. Creative, curious, and confident, you will be an integral part of our empowered, self-managing, multi-disciplinary engineering teams -designing, building, releasing, and maintaining high-quality digital products. You will play a key role in shaping and growing a best-in-class frontend engineering capability, establishing modern development practices and building scalable, high-performance web applications. This is an initial 6-month contract (outside IR35) requiring 3 days per week onsite in Paddington, London. Key Accountabilities Team Leadership Build, mentor, and lead a high-performing team of frontend engineers specialising in React, Next.js, and TypeScript. Foster a culture of collaboration, technical excellence, and...

About Prolific Prolific is not just another player in the AI space – we are building the biggest pool of quality human data in the world. Over 35,000 AI developers, researchers, and organizations use Prolific to gather data from paid study participants with a wide variety of experiences, knowledge, and skills. The role We're looking for Senior Python Developers to join our Expert Network to help train and evaluate cutting-edge AI models. If you have a background in Software Engineering, we'll send you a quick 10- to 15-minute test to assess your skills. If successful, you'll be invited to join Prolific as a participant, where you'll get paid to help AI understand and summarize complex scientific data. Researchers looking for your skills tend to pay up to $50/hr, depending on skills and experience level . You must be prepared to complete paid tasks that require one hour of uninterrupted work , though many are shorter. What you'll bring Educational...

About Us at GoCardless GoCardless is a global bank payment company. Over 100,000 businesses , from start-ups to household names, use GoCardless to collect and send payments through direct debit, real-time payments and open banking.  GoCardless processes US$130bn+ of payments annually, across 30+ countries ; helping customers collect and send both recurring and one-off payments , without the chasing, stress or expensive fees. We use AI-powered solutions to improve payment success and reduce fraud. And, with open banking connectivity to over 2,500 banks , we help our customers make faster, more informed decisions. We are headquartered in the UK with offices in London and Leeds , and additional locations in Australia, France, Ireland, Latvia, Portugal and the United States. At GoCardless, we're all about supporting you ! We’re committed to making our hiring process inclusive and accessible . If you need extra support or adjustments,...

  Job Title: Senior Cloud Engineer (contract) Location: London Hybrid. Travel to the London office 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 experienced Senior Cloud Engineers to work in the Technology and Transformation Team at Deloitte. You will work with one of our global financial services clients. This position requires...

  Job Title: Senior Full Stack Developer (contract) Location: London Hybrid. Travel to the London office 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 Senior 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...

Senior .NET Engineer (Contract) We're looking for a Senior .NET Engineer (Contract) to join our team in London, United Kingdom in a hybrid working mode. In this role, you will focus on building solutions for the finance sector, leveraging AWS and modern engineering practices. You will drive software design and development, ensure seamless integration and performance across complex systems, and maintain high standards of code quality. Responsibilities Design, develop and maintain applications using C# and .NET technologies to deliver robust, scalable solutions Design, develop and maintain software for seamless integration and optimal performance Design and implement solutions for distributed systems and ensure efficient interaction with relational and NoSQL databases Implement and maintain Infrastructure as Code (IaC) using AWS CDK with Python to automate deployment and management of cloud resources...

We are urgently looking for experienced candidates with strong hands-on Java development skills and design experience. While an architect title is not mandatory, we are particularly interested in profiles of senior developers with solid technical expertise. Required Core Skills: - Java - Python - GoLang -Design, develop, and maintain high-quality Java applications. -Write clean, efficient, and well-documented code. -Perform code reviews and optimize existing codebases. -Ensure application performance and reliability. -Develop and maintain automated tests to ensure code quality. -Work with CI/CD pipelines to streamline the development and deployment process. Job Types: Full-time, Freelance Pay: £350.00-£370.00 per day Schedule: Monday to Friday Experience: Java: 7 years (required) Python: 3 years (required) Go: 2 years (required)

WWT EMEA has an opportunity for a Senior Node.js Engineer to modernize and rebuild internal Node.js‑based package manager into a fully supported product.   The successful candidate will be developing a cross‑platform CLI tool for Windows and macOS, integrating with Artifactory, and supporting governance and distribution processes for portable developer tools.   This is a contract Role & Inside IR35   Senior Node.js Engineer   Contract Duration: 9 months Contract   Location: Remote, United Kingdom (Occasional travel to London as per business need)     Key Responsibilities: Modernize and rebuild internal Node.js-based package manager into a fully supported product. Develop a cross‑platform CLI tool (Windows + macOS) that supports package discovery and installation. Integrate the CLI with Artifactory for tool, SDK, runtime, and FOSS package distribution. Support governance for...

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...

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...

Job Title: Senior Full Stack Developer (contract) Location: London Hybrid. Travel to the London office 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 Senior 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 a solid understanding of...

Job Title: Senior Cloud Engineer (contract) Location: London Hybrid. Travel to the London office 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 experienced Senior Cloud Engineers to work in the Technology and Transformation Team at Deloitte. You will work with one of our global financial services clients. This position requires a solid engineering experience as...

Senior Full Stack Engineer ( Finance Experience Required )   London | Contract | Outside IR35 | Conquer AI   We’re hiring a Senior Full Stack Engineer at Conquer AI.   This is a hands-on engineering role for someone who can work across the stack, but with real strength in backend systems, data, and platform architecture. You’ll be joining us to help deliver a high-impact project in a complex, commercially critical environment.   This is not a pure frontend role. This is not a role for someone who wants to stay at the architecture-diagram level. We’re looking for someone who can take messy business processes, turn them into clear technical systems, and ship production-grade software.   What you’ll do Build and evolve workflow platforms that support intake, approvals, pipeline management, and execution handoffs Design and deliver APIs, services, and integrations across internal...

ABOUT THE COMPANY Onmo believes that everyone has the right to access, understand and manage their money with confidence. Our ambition is to improve lives by providing better clarity, intelligence and technology to empower every individual in making the smartest financial decisions. We may be young but we have an incredible team in place and big ambitions for the years ahead. We design our products to help demystify money matters wherever possible, providing customers with more financial control and flexibility in their lives. This helps them get more from what they have, or with smart decisions, make more of the same. It also means people spend less time with the negative aspects of money and more on the positive - enjoying what the world has to offer. ABOUT THE ROLE Tech Stack Backend : AWS Serverless Service, including Lambda, API Gateway, DynamoDB, S3, SNS, SQS, EventBridge, Kinesis, Node.js, YAML Frontend : React / Next.js, React Native Programming...

We currently have an urgent opening for a skilled DevOps Engineer to join us on a contract basis ASAP. This is a major Greenfield platform build for a UK bank. Joining a cross functional team of 14, in the Infrastructure / DevOps phase of building a brand new payments platform from scratch. Required skills: Terraform AWS (some Azure) Kubernetes Secure enterprise platform development experience Account and user policies CI/CD pipeline development 2 days in person working (Monday & Weds - Canary Wharf) START DATE MONDAY 30th MARCH   The role   We're looking for a Senior DevOps / Platform Engineer to join a specific project with a leading UK Bank. Red Badger delivers high quality digital products using a lean delivery process and multidisciplinary, cross-functional teams. The Senior DevOps / Platform Engineer has deep expertise in building and operating digital products,...