27 contract software engineer jobs found in London

Senior Java & Kotlin Backend Engineer Location: London (Hybrid - Wednesday office attendance required) Contract: Initial 2 months IR35: Outside IR35 Start Date: ASAP The Role We're working with a leading technology organisation seeking an experienced Senior Java & Kotlin Backend Engineer to join their engineering team on an initial two-month contract click apply for full job details

Senior Java & Kotlin Backend Engineer Location: London (Hybrid - Wednesday office attendance required) Contract: Initial 2 months IR35: Outside IR35 Start Date: ASAP The Role We're working with a leading technology organisation seeking an experienced Senior Java & Kotlin Backend Engineer to join their engineering team on an initial two-month contract. This role offers the opportunity to contribute to greenfield backend development, building scalable, cloud-native microservices within a modern engineering environment. You'll work alongside cross-functional teams to design, develop and deliver high-quality backend solutions that are secure, reliable and built for scale. Key Responsibilities Design, develop and maintain backend services using Java and Kotlin. Build and enhance RESTful APIs within a microservices architecture. Develop secure, scalable and high-performance applications. Collaborate with Product Managers, Engineers and technical...

Senior Java & Kotlin Backend Engineer Location: London (Hybrid - Wednesday office attendance required) Contract: Initial 2 months IR35: Outside IR35 Start Date: ASAP The Role We 're working with a leading technology organisation seeking an experienced Senior Java & Kotlin Backend Engineer to join their engineering team on an initial two-month contract. This role offers the opportunity to contribute to greenfield backend development, building scalable, cloud-native microservices within a modern engineering environment. You 'll work alongside cross-functional teams to design, develop and deliver high-quality backend solutions that are secure, reliable and built for scale. Key Responsibilities Design, develop and maintain backend services using Java and Kotlin. Build and enhance RESTful APIs within a microservices architecture. Develop secure, scalable and high-performance applications. Collaborate with...

Senior Java & Kotlin Backend Engineer Location: London (Hybrid - Wednesday office attendance required) Contract: Initial 2 months IR35: Outside IR35 Start Date: ASAP The Role We're working with a leading technology organisation seeking an experienced Senior Java & Kotlin Backend Engineer to join their engineering team on an initial two-month contract. This role offers the opportunity to contribute to greenfield backend development, building scalable, cloud-native microservices within a modern engineering environment. You'll work alongside cross-functional teams to design, develop and deliver high-quality backend solutions that are secure, reliable and built for scale. Key Responsibilities Design, develop and maintain backend services using Java and Kotlin. Build and enhance RESTful APIs within a microservices architecture. Develop secure, scalable and high-performance applications. Collaborate with Product Managers, Engineers and technical...

Candidate Specification - SourceWise Solutions Staff Software Engineer (Backend / Platform) This is a remote contract role with occasional visits to the client's office when required. The engagement is Outside IR35, offering a daily rate of £500 About SourceWise SourceWise Solutions partners with innovative global technology companies to build high-performing engineering teams. We connect experienced engineers with organisations building modern, scalable software platforms. About the Opportunity This Staff Software Engineer role is with one of our international technology clients. You will influence architecture, engineering practices, and technical direction while solving complex, high-impact problems. Key Responsibilities · Lead architecture and design of scalable distributed systems. · Own complex cross-team engineering challenges. · Drive technical strategy and influence engineering decisions. · Improve platform scalability, reliability,...

Candidate Specification - SourceWise Solutions Staff Software Engineer (Backend / Platform) This is a remote contract role with occasional visits to the client's office when required. The engagement is Outside IR35, offering a daily rate of £500 About SourceWise SourceWise Solutions partners with innovative global technology companies to build high-performing engineering teams. We connect experienced engineers with organisations building modern, scalable software platforms. About the Opportunity This Staff Software Engineer role is with one of our international technology clients. You will influence architecture, engineering practices, and technical direction while solving complex, high-impact problems. Key Responsibilities · Lead architecture and design of scalable distributed systems. · Own complex cross-team engineering challenges. · Drive technical strategy and influence engineering decisions. · Improve platform scalability, reliability, and maintainability. ·...

Embedded Software Engineer | 6-Month Contract (Outside IR35) | CambridgeLocation: Cambridge, UK (Onsite) Contract Type: 6 months (Outside IR35) Rate: Competitive (DOE) Responsibilities: Develop embedded software in C (Linux environment) Design, implement, and maintain device drivers Work closely with hardware and systems engineers onsite Required Experience: 3+ years’ embedded software development experience Strong C programming skills in Linux environments Experience with device drivers or kernel-adjacent development Apply: If you're looking for a 6-month Outside IR35 contract in Cambridge, apply with your CV today.

🚨 Senior Playwright SDET | £700/day | Outside IR35 | Front Office Trading | London I'm working with a leading global investment bank looking to hire an exceptional Playwright SDET to join their Front Office Derivatives Technology team. This isn't your typical automation role. You'll be embedded within a high-performing engineering team, working directly alongside developers on a strategic front end trading platform. The rate reflects the calibre of engineer they're looking for. 💰 Package £700 per day Outside IR35 12-month rolling contract 1 day per week in the London office What they're looking for This role is suited to a highly technical SDET who is passionate about automation and enjoys writing production-quality code. You must have: ✅ Strong commercial experience with Playwright ✅ Excellent coding skills in JavaScript and TypeScript ✅ Experience building and maintaining automation frameworks ✅ Previous experience working on...

Technical Project Manager/Scrum Master (Hands-on Development) - Hybrid London Start Date: August/September 2026 Duration: 3-6 months (Likely Extensions) Day Rate: £800-£900 per day (Negotiable) IR35 Status: Outside IR35 Location: London (Hybrid - Minimum 3 days per week onsite) Key Skills & Experience: Technical Leadership & Delivery Proven experience operating as a Technical Project Manager, Scrum Master or Technical Delivery Lead. Strong Agile delivery experience across multiple software development teams. Experience managing complex technical projects within Banking or Capital Markets. Comfortable managing both technical delivery and stakeholder expectations. Strong understanding of software development life cycle, Agile methodologies and engineering best practices. Hands-on Software Development: This is a hands-on technical role. Candidates must remain technically active and able to contribute directly to software development....

Remote Contract (UK Candidates only) Ideal start date: ASAP Contract Duration: 6 Months Outside IR35 Rate: £500-600 p/d Elsewhen, a London-based consultancy, designs and builds technology solutions for clients like Spotify, Google, Inmarsat, and Zego. Over the past decade, we have built a workplace prioritising impact, drive, and friendliness. We value outcomes over hours and agility over rigid processes. Work Environment: Fully Remote in the UK Join our team:https://www.elsewhen.com. We are looking for a talented Senior AI Engineer to join a brand new delivery squad focused on solving new client problems in 4-week cycles. Each project is designed to produce a working pilot that demonstrates clear value, not a polished long-term system. You’ll work in a 4-person team (AI Engineer, Product Manager, Data Scientist, Principal for AI Engineering), using AI coding tools (e.g. Claude Code) to reduce build time and get solutions into a...

Data Science AI Engineer - RAG Chatbot LangGraph exp London - Hybrid. Circa £500 - £675 per day (and negotiable DOE) Contract (Outside IR35) Agentic AI/Machine Learning. Company: Our client is a globally established B2B information and professional services business, operating across multiple high-value industry sectors. They have established data science and machine learning engineering teams already delivering in production, and are now expanding their AI capability significantly across the global organisation. This is a high-impact role with strong visibility across the organisation , working closely with product managers, engineers, and other data scientists to design and deploy AI, agentic and chatbot solutions that improve the quality of our products and automate complex workflows. You'll have the opportunity to work across the full lifecycle of data science: exploration, modelling, experimentation, and production deployment - while contributing to...

QA Engineer – Remote | £475–£500/day | Outside IR35 - 3 Month Contract We are looking for an experienced QA Engineer to join our team on a 3 month contract. This role is paying £475–£500 per day and is Outside IR35 . You will be responsible for ensuring the quality and reliability of API integrations and payment-related workflows, working closely with developers to validate new features, identify defects, and support the delivery of robust, high-quality software. Core Requirements Strong commercial experience testing C#/.NET APIs Hands-on experience with testing tools such as Postman, REST Assured, Playwright , or similar automation/testing frameworks Experience testing webhooks , asynchronous event-driven workflows , and terminal/POS transaction flows Solid understanding of API testing, debugging, and validating request/response behaviour Experience creating and executing test cases, identifying defects, and working collaboratively with development...

Full Stack Engineer - Azure, C#, .Net, React / ReactJS Outside IR35 12 Month Contract Fully Remote (UK only) £375 - 425 Per Day We 're currently working with a London based MedTech company who are searching for a Full Stack Engineer who has extensive experience working with Azure, C#, .Net and React / ReactJS. This project will see you working alongside a small existing team of developers, adding additional capacity to make business critical updates and enhancement to their existing Azure based core platform, with the bulk of the work will focus on enhancing the workflow engine! We are looking for an experienced Full Stack Engineer who is comfortable working on complex software platforms and is able to get up to speed quickly in new environments. Required Skills / Experience Extensive commercial experience with: Azure - Azure Functions, Azure API Management, Azure Services, Azure B2C Directory, Azure...

We're working with an innovative UK technology business that's transforming the way scientific organisations analyse complex imaging data. They're entering an exciting phase of product development as they evolve a proven proof-of-concept into a scalable, enterprise-grade AI SaaS platform. They're looking for a Senior Full Stack Engineer to join the team on an initial 6-month contract, taking ownership of key platform features across the full technology stack while helping shape the technical direction of a next-generation AI product. You'll play a key role in building a production-ready, cloud-native SaaS platform that combines modern web technologies with machine learning capabilities. Working closely with Product, Design and Engineering, you'll take features from concept through to deployment, delivering scalable, secure and maintainable solutions. This is a hands-on engineering role with plenty of autonomy, ideal for someone who enjoys working in fast-moving product...

Job Title: NiFi Data Engineer Location: Hybrid (up to 3 days per week on-site, across offices in London & South England) Contract Length: 8 Months (with scope to extend) Start Date: September 2026 IR35: Outside Interview Process: 1 Stage, MS Teams Clearance Required Before Applying: SC (with eligibility for higher levels of clearance) We are supporting a public sector client in hiring a NiFi Data Engineer to join a collaborative development team delivering a data Lakehouse architecture across both cloud and on-premises platforms. This is a hands-on data engineering role working within Agile sprints across a full software development life cycle, building and maintaining data pipelines, developing data models and handling non-functional requirements including security, performance and metadata labelling. The successful candidate will work closely with engineers and architects to deliver robust, well-tested pipelines that support a modern Lakehouse...

Data Science AI Engineer - RAG Chatbot LangGraph exp London - Hybrid. Circa £500 - £675 per day (and negotiable DOE) Contract (Outside IR35) Agentic AI / Machine Learning. Company: Our client is a globally established B2B information and professional services business, operating across multiple high-value industry sectors. They have established data science and machine learning engineering teams already delivering in production, and are now expanding their AI capability significantly across the global organisation. This is a high-impact role with strong visibility across the organisation , working closely with product managers, engineers, and other data scientists to design and deploy AI, agentic and chatbot solutions that improve the quality of our products and automate complex workflows. You'll have the opportunity to work across the full lifecycle of data science: exploration, modelling, experimentation, and...

Remote Contract (UK Candidates only) Ideal start date: ASAP Contract Duration: 6 Months Outside IR35 Rate: £500-600 p/d Elsewhen, a London-based consultancy, designs and builds technology solutions for clients like Spotify, Google, Inmarsat, and Zego. Over the past decade, we have built a workplace prioritising impact, drive, and friendliness. We value outcomes over hours and agility over rigid processes. Work Environment: Fully Remote in the UK Join our team:https://www.elsewhen.com. We are looking for a talented Senior AI Engineer to join a brand new delivery squad focused on solving new client problems in 4-week cycles. Each project is designed to produce a working pilot that demonstrates clear value, not a polished long-term system. You’ll work in a 4-person team (AI Engineer, Product Manager, Data Scientist, Principal for AI Engineering), using AI coding tools (e.g. Claude Code) to reduce...

We are seeking an experienced and customer-focused Senior 2nd Line Support Engineer to become the face of IT for a busy corporate office in West London. This is more than a traditional desktop support role. You will act as the primary onsite technology partner for approximately 100 users, delivering an exceptional support experience while working closely with an external Managed Service Provider (MSP) to continually improve service delivery. The successful candidate will combine excellent technical capability with outstanding customer service, strong stakeholder management and the ability to take ownership of small technology projects and operational improvements. Location: West London (On-Site) Working Pattern: 4-5 days per week on-site Contract: Initial 6 months Start: ASAP Key Responsibilities End User Support Deliver high-quality onsite 2nd Line support for approximately 100 users Resolve hardware, software and application issues quickly and...

Location: London (Central)  Contract Length: 6 Months (minimum) Rate: £65 p/h (Outside IR35) Start Date: ASAP An exciting opportunity has arisen for an experienced Control Systems Engineer to join a leading systems integration team delivering automation solutions in the energy sector. You'll be responsible for developing and commissioning Siemens based control systems, supporting projects from software development through to site commissioning. This is an ideal opportunity for an engineer who enjoys technically challenging projects and is comfortable working both remotely and on customer sites. Key Responsibilities Design and develop PLC software using Siemens TIA Portal Configure Siemens HMI/SCADA systems where required Produce and modify functional design specifications Carry out software testing, FAT and SAT activities Diagnose and resolve technical issues during commissioning Ensure projects are delivered safely, on time and to specification Expereince...

Data Engineer (Modelling) - Contract UK Remote 6-Month Contract | Competitive day rate | Outside IR35 About the role Are you a specialist data modeller who does your best work under a clear brief and a defined timeframe? Do you take pride in leaving behind data models that are cleaner, better documented and more useful than what you found? At Haven, great holidays are powered by great data and we're bringing in a Data Engineer (Modelling) on a 6-month outside-IR35 contract to strengthen the modelling craft at the heart of our data platform. This is a hands-on, delivery-focused engagement for a seasoned dimensional modeller who can hit the ground running, integrate quickly into a squad, and start shipping high-quality Kimball models in dbt from week one. This contract role is focused on designing and evolving dimensional models across guest, booking, revenue and operational domains, sharpening our semantic layer in dbt, and raising the bar on data quality,...