12 back end engineer jobs found in London

Back End Engineer (contract) Opus have partnered with an cutting-edge AI focused HealthTech start-up with a mission-driven culture and ethical AI approach. The successful candidate will be making a real impact to patient care outcomes. Contract Specifics: Rate: £400 per day, Outside IR35 Duration: 3 months Start date: ASAP, Immediate starter Working Patterns: Full-time, 1 day p/w in London-offices. Essential: Confident working across data infrastructure, distributed systems, APIS and AI-services Proven experience in building/designing scalable Back End services Strong experience building and maintaining APIs (REST, GraphQL and/or gRPC). Knowledge of Docker and AWS (ideally in a recent project) Essential - must have strong coding skills in Python, Typescript, Node and SQL. Nice to have : Docker, ECS, Kubernetes or similar container platform experience Familiarity with Django frameworks and IaC (eg Terraform) Experience with the deploying...

Back-end Engineer (contract) Opus have partnered with an cutting-edge AI focused HealthTech start-up with a mission-driven culture and ethical AI approach. The successful candidate will be making a real impact to patient care outcomes. Contract Specifics: Rate: £400 per day, Outside IR35 Duration: 3 months Start date: ASAP, Immediate starter Working Patterns: Full-time, 1 day p/w in London-offices. Essential: Confident working across data infrastructure, distributed systems, APIS and AI-services Proven experience in building/designing scalable backend services Strong experience building and maintaining APIs (REST, GraphQL and/or gRPC). Knowledge of Docker and AWS (ideally in a recent project) Essential - must have strong coding skills in Python, Typescript, Node and SQL. Nice to have : Docker, ECS, Kubernetes or similar container platform experience Familiarity with Django frameworks and IaC (e.g. Terraform)...

Leading Ecommerce client now requires a Full Stack JavaScript Developer who is proficient in front and Back End development. (React/TypeScript/Node.js). This role will design and build the foundations of which our clients innovative web and mobile applications run on. Key Responsibilities: Working as an integral part of an agile team contributing towards the planning and development of systems/platforms. Collaborating with engineers, product owners and business analysts to define solutions, ways of working and share knowledge across the department. Reviewing code and providing support to members of your team. Working on client-facing applications in react/next.js Designing and building Node.js/GraphQL APIs. Key Requirements: Senior level experience in modern JavaScript, written with Typescript, Node.js, React, Next.js etc. Previous experience using Stripe & Salesforce is highly desirable. Experience designing and developing APIs/microservices....

BI/Data Engineer As a BI/Data Engineer, you will provide specialist technical expertise to develop, enhance and support our outbound bordereaux reporting solution. Working closely with the Actuarial, Product, Data & MI teams, you will improve data quality, implement new reporting requirements and automate manual processes to deliver accurate, timely and efficient bordereaux submissions to our capacity providers. You will take ownership of understanding the existing solution, analysing business requirements, developing robust data validation processes and delivering scalable reporting solutions while ensuring knowledge is documented and transferred at the conclusion of the engagement. Essential Experience Proven experience developing bordereaux reporting solutions within the insurance industry. Strong experience as a BI Developer or Data Engineer. Hands-on experience working with the Acturis Back End database. Advanced SQL skills including stored procedures, views,...

Senior Software Engineer - Kotlin £550-£650 per day | Outside IR35 Hybrid | London (3 days onsite) A leading UK financial services organisation is seeking a Senior Software Engineer to play a central role in a large-scale platform transformation programme. The business is rebuilding a critical part of its digital infrastructure to support a broad range of transaction methods and channels across both in-person and digital environments. This is hands-on Back End engineering at scale, with real ownership and direct exposure to architecture decisions from day one. Key Responsibilities as a Senior Software Engineer: Design and build Kotlin Back End services for a new payments platform Own the architecture and design of key components, taking high-level requirements and turning them into structured, deliverable backlogs Write clean, well-tested, production-ready code that the team can rely on Work closely with Product and Engineering to break down complex...

ML Engineer (Early Career - Mid-level) New contract role | Immediate starter - Just in! Opus have partnered with an cutting-edge AI focused HealthTech start-up with a mission-driven culture and ethical AI approach. The successful candidate will be making a real impact to patient care outcomes. Contract Specifics: Rate: £400 per day, Outside IR35 Duration: 3 months Start date: ASAP, Immediate starter Working Patterns: Full-time, 1 day p/w in London-offices. Person Specification: - Solid skills in Python, SQL and AWS. - Background in Software Engineering/Data Engineering | Previous Back End work is nice to have - Experience working with ML models (productisation, not just for research/prototyping) Nice to have: - A deeper understanding on ML Models/ML Data Science from an API perspective (GraphQL, gRPC, REST) - Start-up or HealthTech experience. This is an urgent requirement, please reach out ASAP to Adam Akhtar today (17th July) to...

Senior Software Engineer - Kotlin & Coroutines. £500/day LTD CO OUTSIDE IR35. 100% REMOTE. An interest in AI (Agentic AI, AI tooling, Claude, Codex or Co-Pilot) highly advantageous but not essential. We are looking for a Senior Backend Engineer (Kotlin & Coroutines essential) to build the integrations that connect AI companion with senior care and hospital software platforms. In this role, you will design, build, and maintain robust Back End services and integrations that enable seamless data exchange between the company and partner systems. You'll take end-to-end ownership of integration projects-from discovery and architecture through implementation, deployment, and continuous improvement. Key Responsibilities for the Kotlin & Coroutines Developer are: Design, develop, and maintain integrations between my clients platform and third-party healthcare and senior care software systems. Build scalable, secure, and maintainable Back End services and APIs using...

Leading eCommerce client now requires a Senior Backend Engineer to join their Platform Team and contribute towards the design and development of high volume, scalable and resilient E-commerce platforms. The role: Building Back End services and APIs in Node.js. Working with AWS SQS, SNS, and Lambda for event-driven architecture. Practicing TDD and applying DDD to model complex business domains. Collaborating with a platform team on systems handling serious traffic and transaction volume. Key Requirements: Strong senior-level Node.js and TypeScript experience. Hands-on cloud experience with AWS (SQS, SNS, Lambda). Solid API design and development background. Real hands-on experience with TDD and DDD, not just familiarity. Microservices experience, CI/CD, observability tooling. Excellent communicator with a strong background in pair programming and cross functional collaboration. This is an initial 6-month contract role which provides a daily rate...

AI Integration Engineer (Defence & National Security) Location: London (Hybrid) Contract Rate: £600/day (Outside IR35) Requirement: Active UK SC Clearance (Mandatory) We are hiring on behalf of our client, a specialised defence consultancy, who is looking for an AI Integration Engineer with active SC clearance to join them on a contract basis in London. Key Skills Required Active UK SC Clearance (Mandatory - applications without this cannot be considered) Core Engineering: Strong Back End development skills (Python, Go, or C++) with solid API design and data pipeline experience AI Tooling: Hands-on experience integrating LLMs, handling vector databases, and building robust chunking/embedding strategies Secure Architecture: Deploying LLM pipelines, RAG systems, and orchestration layers within secure, classification-bound environments Local Implementations: Self-hosting, optimising, and containerising open-source models (eg, Llama,...

First Point Group is recruiting for BTS Installation & Commissioning Engineers to support a major nationwide DICI deployment in Manchester or London regions. These roles are outside IR35. PLEASE NOTE - Sponsorship cannot be provided. Candidates must live in the UK with valid rights to work. Candidates should be based in or around London or Manchester and be willing to travel if required. BTS Installation & Commissioning Engineer Location: London / Manchester The Opportunity We are looking for 3 experienced BTS Installation & Commissioning Engineers to provide additional delivery capacity on a major nationwide DICI deployment. You will be responsible for the installation, commissioning, testing and acceptance of Nokia BTS equipment across multiple customer sites, ensuring all work is completed safely, accurately and in line with customer SLAs. Key Responsibilities Install and commission Nokia BTS equipment including baseband...

🚨 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...

UI Architect Global Financial Services/Payments Client Location: London - 4 days per week Rate: £550-£570 per day Contract: 6 months initial IR35 Status: Outside IR35 Role Overview We are supporting a global financial services organisation operating in cross-border payments and emerging markets as they continue a large-scale technology transformation. They are looking for an experienced UI Architect to lead the design and delivery of scalable, modern Front End platforms aligned to a microservices architecture. This is a hands-on architecture role with responsibility for defining standards, driving best practice and shaping the Front End ecosystem across multiple products. Key Responsibilities Define and own Front End architecture across a microservices-based platform Design scalable UI solutions aligned to API-first Back End services Establish reusable components, UI standards and enterprise design systems Define integration approaches with RESTful and...