16 senior backend developer jobs found

Senior Backend Developer (Fully Remote, Node.js) Contract: Outside IR35 Duration: 3 months, potential extension Start: ASAP Day Rate: £550/day Location: Fully Remote (UK hours)   The Role You'll join as a peer alongside our existing senior developers. You'll own features and integration workstreams end to end, with collaboration through code review and shared technical decision-making.   The work splits roughly 75/25 between API development for our FHIR-based clinical platform and third-party integrations. Genuinely interesting domain problems, not generic CRUD. Features are scoped collaboratively with product. You'll own implementation through to deployment, with your peer as code review partner.   What you'll work on Building and extending RESTful APIs in TypeScript and Node.js Integrating with third-party platforms including cal.com, Awell (clinical workflow engine) and healthcare data...

About Us We are a technology solutions provider specialising in the public sector. Our mission is to help government organisations become truly data-driven by transforming their digital services, streamlining operational processes, improving citizen outcomes, and enhancing transparency across public services. We work closely with government bodies to design and deliver modern, secure, and scalable digital solutions that have real-world impact. The Role We are looking to engage a Full Stack Developer on a contract basis to support the delivery of high-quality digital services within the UK public sector. You will play a key role in designing, building, and maintaining robust full-stack applications, working closely with multidisciplinary teams including product managers, designers, and other engineers. This role requires a hands-on senior developer who is comfortable working across the full software development lifecycle and who understands the standards,...

We are looking for a talented Web Engineer to join our growing team. In this role, you will help develop and maintain high-performance web applications, collaborating closely with senior engineers and tech leads. You will contribute to cloud deployments, CI/CD pipelines, and scalable architecture while gaining hands-on experience with a modern tech stack.   Employment Type This is a full-time independent contractor position. We are not currently hiring for direct employee positions. Location This is a fully remote position. Work where you perform your best.   Key Responsibilities Develop and maintain web applications using PHP7, Next.js, NestJS, Typescript, JavaScript, HTML, CSS, Vue, and Webflow. Assist in designing and deploying cloud infrastructure on AWS, GCP, and Azure. Support CI/CD pipeline management using Artifactory, Docker, and Kubernetes. Collaborate with database engineers to ensure efficient MySQL...

We are looking for a Test Lead/ Manager to join our crew! You’ll play a key role in driving our ambition to build a best-in-class engineering culture—where quality, collaboration, and continuous improvement sit at the heart of everything we do. We’re looking for an experienced Test Manager to join our client's Loyalty team and help deliver seamless, high-quality digital experiences to millions of customers. You’ll lead the testing strategy and ensure the reliability of systems that integrate personalized offers and mission-based rewards into our customer journey. Working closely with developers, data scientists, and the core loyalty platform team, you’ll help create a modern digital ecosystem powered by data and built with cutting-edge technology.   This is an initial 6 month contract (outside IR35). You will be required on client site 3 days a week in Paddington, London.   What You’ll Do: Test Leadership...

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 instruments and systems. Bonus...

Toucanberry Tech is a UK-based boutique software consultancy delivering high-impact solutions to the financial sector. You’ll be joining a pivotal project, building a cutting-edge reinsurance platform from the ground up for a global reinsurer in Bermuda. ROLE: We are looking for a hungry and hands-on Product Owner to join our dedicated onshore team. This is not a project management role; we need a modern start up Product Owner who lives and breathes the product, sits side-by-side with our developers, and is passionate about building exceptional backend, data-centric solutions. Key Responsibilities: Own and manage the product backlog, translating high-level business requirements into clear, actionable user stories for the development team. Collaborate daily with a co-located, onshore squad of engineers, QAs, and designers to ensure seamless delivery and a shared understanding of the product vision. Define and analyse metrics to inform the success of the...

Location: Fully Remote Team: Tech Team Employment Type: Contract Tangible is a fast-growing, tech-driven platform providing liquidity solutions to LPs and GPs in the private-markets secondaries space. By combining deep sector expertise with modern infrastructure, we unlock liquidity across private equity, private credit, and real assets, transforming the industry and enabling investors to move faster and smarter. We are looking for a Platform Engineer/SRE to own Tangible’s cloud infrastructure, system reliability, and core platform services. This role goes beyond traditional DevOps. You will be responsible for availability, scalability, and resilience, while also building and maintaining core internal services in Python and Node.js that enable product teams to move fast and safely. Tasks Own and operate Tangible’s AWS infrastructure, ensuring high availability, reliability, and performance Act as the primary owner of system uptime, incident response,...

Location: Fully Remote Team: Tech Team Employment Type: Contract Tangible is a fast-growing, tech-driven platform providing liquidity solutions to LPs and GPs in the private-markets secondaries space. By combining deep sector expertise with modern infrastructure, we unlock liquidity across private equity, private credit, and real assets, transforming the industry and enabling investors to move faster and smarter. Tasks Design, develop, and maintain robust, scalable application features and services. Contribute to both client-facing and server-side components of the platform. Write clean, readable, and well-tested code following engineering best practices. Participate in architectural discussions and contribute to system design decisions. Collaborate closely with QA, DevOps, Product, and Design teams. Review code, participate in pull requests, and support pair programming. Share knowledge, contribute to documentation, and support onboarding...

Location: Fully Remote (accepting applications globally) Team: Tech Team Employment Type: Contract * *Company Description * * Tangible is a fast-growing, tech-driven platform providing liquidity solutions to LPs and GPs in the private-markets secondaries space. By combining deep sector expertise with modern infrastructure, we unlock liquidity across private equity, private credit, and real assets, transforming the industry and enabling investors to move faster and smarter. We’re looking for a smart, curious AI-driven Test Automation Engineer who loves breaking systems, automating the boring stuff, and using AI as a daily co-pilot. This role is heavily Cursor-driven, focused on building and evolving automated tests using Cypress, while understanding both manual QA procedures and automation principles. You don’t need 10 years of QA experience: we care more about how you think, how fast you learn, and how well you use AI to amplify your impact....

We are looking for a true Polyglot Engineer to join our team for a long-term collaboration. In the fragmented world of Web3, the ability to bridge different technologies is a superpower. We need a specialist who can architect and build the critical off-chain infrastructure that powers decentralized applications. If you are proficient in Rust but comfortable diving into C++, Python, and Node.js to get the job done, this role is for you. Who are we? We are Out Of The Box Systems: a Ukrainian team of passionate, battle-tested engineers and creators united by one goal—delivering real results with clarity, precision, and autonomy. We champion a flexible, pragmatic approach over rigid, static processes. While our roots and primary team are in Ukraine, we collaborate with top talent from various labor markets. We specialize in demanding fields like Rust-first development, AI Engineering, and Computer Graphics, blending performance, security, and innovation into every...

Toucanberry Tech is a UK-based boutique software consultancy delivering high-impact solutions to the financial sector. You’ll be joining a pivotal project, building a cutting-edge reinsurance platform from the ground up for a global reinsurer in Bermuda. ROLE: We are looking for a hungry and hands-on Product Owner to join our dedicated onshore team. This is not a project management role; we need a modern start up Product Owner who lives and breathes the product, sits side-by-side with our developers, and is passionate about building exceptional backend, data-centric solutions. Key Responsibilities: Own and manage the product backlog, translating high-level business requirements into clear, actionable user stories for the development team. Collaborate daily with a co-located, onshore squad of engineers, QAs, and designers to ensure seamless delivery and a shared understanding of the product vision. Define and analyse metrics to inform the success of the...

Toucanberry Tech is a UK-based boutique software consultancy delivering high-impact solutions to the financial sector. We work in agile, cross-functional teams to solve complex challenges with speed, autonomy, and innovation. The Role We are looking for a hands-on Data Product Owner to join our dedicated onshore team. We need someone with a start up mindset who lives and breathes the product, sits side-by-side with our developers, and is passionate about building exceptional backend, data-centric solutions. Key Responsibilities: Owning the end-to-end data lifecycle, from ingestion and transformation through to modelling, analysis, and visualisation. Converting disparate raw data into reliable, structured datasets ready for modelling, analysis, and visual reporting. Managing the product backlog, translating high-level business requirements into clear, actionable user stories. Leading a high-performing squad of engineers and analysts to ensure seamless...

At Valcon, we are a European Powerhouse in data, cloud, and AI-driven business transformation. We combine deep technical expertise with our heritage in operational excellence, failsafe delivery, and organisational change. Trusted by Europe's leading organisations, we don't just advise - we implement and deliver sustainable transformation. Backed by private equity, Valcon has brought together leading firms to form one of Europe's fastest-growing consultancies. In the UK, we're scaling quickly while maintaining a collaborative, hands-on, and down-to-earth culture. The Opportunity Valcon UK is looking for an AWS Architect to play a key role in shaping and delivering our cloud and technology agenda. This is a senior, client-facing role with responsibility for designing, leading, and delivering AWS-based solutions that enable real business outcomes. Cloud is central to how Valcon creates value. Our work spans cloud strategy, platform modernisation, data and AI enablement, and...

Senior Solutions Architect (Shopify Expert) - Contractor Full job description About Avex Avex is a rapidly growing eCommerce agency that partners with merchants in the fashion, lifestyle and premium products space. From high-growth DTC brands to enterprise, we have partnered with companies such as: Khaite, Quip, KITH, Stoney Clover Lane, Love Shack Fancy, LVMH, Arizona Beverages, TAG Heuer, Hugo Boss, Enjoy Life, Mondelez, O'Neill, Serta Simmons Bedding and many others. We design, build and optimize eCommerce experiences on Shopify Plus for global brands.   Our Values BUILD our clients’ businesses, INSPIRE our employees to grow, CHALLEN GE the norm, and DELIVER on our commitments. We design and build digital commerce experiences that connect brands to people through creative, technology and culture. We believe that our work should not only produce amazing results for our clients but should also be fun and rewarding for our...

About The Role : This role is to support the delivery of the Finance Service Offer Programme and more specifically the Finance Service Offer Change Project. Finance does not currently have a clear Finance Blueprint or Operating Model, leading to disparity between what Finance delivers and what our partners value and need. There is a lack of clarity on team's roles, responsibilities and priorities, causing blurred lines of governance and causing processes and approvals to be delivered inefficiently and ineffectively. This programme aims to address these issues and to develop a clearly defined Finance Service Offer (FSO). This will be achieved through developing a structured and strategic Finance Operating Model that aligns with organisational priorities and Government Functional Standards (GovS006).   The FSO Change Project is the first step for this as it is focused on transforming financial planning and ownership by simplifying systems, clarifying responsibilities,...

Toucanberry Tech is a UK-based boutique software consultancy delivering high-impact solutions to the financial sector. You’ll be joining a pivotal project, building a cutting-edge reinsurance platform from the ground up for a global reinsurer in Bermuda. ROLE: We are looking for a hungry and hands-on Product Owner to join our dedicated onshore team. This is not a project management role; we need a modern start up Product Owner who lives and breathes the product, sits side-by-side with our developers, and is passionate about building exceptional backend, data-centric solutions. Key Responsibilities: Own and manage the product backlog, translating high-level business requirements into clear, actionable user stories for the development team. Collaborate daily with a co-located, onshore squad of engineers, QAs, and designers to ensure seamless delivery and a shared understanding of the product vision. Define and analyse metrics to inform the success of the...