42 back end engineer jobs found

CONTRACT AI BACKEND ENGINEER (OUTSIDE IR35) Agentic AI Claude Code GitHub Copilot C# / .NET AI Engineering Outside IR35 Hybrid Working (2 Days Onsite in Greater Manchester) £500 - £580 Per Day Outside IR35 Initial 3 Month Contract CONTRACT AI BACKEND ENGINEER We're looking for an experienced AI Backend Engineer to join a forward-thinking engineering team where Agentic AI is becoming a core part of software delivery . Strong commercial experience with C# and .NET remains essential , but what really sets this opportunity apart is the chance to help shape how AI is adopted across the engineering function. We're looking for someone who doesn't just use Claude Code, GitHub Copilot, Cursor or OpenAI to write code-they understand how to build effective AI-assisted engineering practices that improve quality, consistency and delivery across an entire team. Working closely with the Principal Engineer and Principal Architect , you'll remain hands-on building...

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)  Experience with the deploying and operating ML or...

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)...

We're hiring a React Native engineer to build a mobile app for a large regulated UK organisation. It's used at scale, so dependable, accessible mobile matters a lot here. What you'll do: Build and ship a cross-platform app in React Native and TypeScript. Deliver for both iOS and Android. Keep accessibility front of mind throughout. Work with backend and design to ship features end to end. What we're looking for: Strong React Native and TypeScript. Proven experience shipping apps to the App Store and Play Store. Good grasp of mobile accessibility. Solid understanding of mobile performance and testing. Comfortable using AI-assisted development tools like GitHub Copilot as part of your everyday workflow. Bonus points for financial services or regulated-app experience. About hedgehog lab: We're hedgehog lab, a digital product and engineering consultancy. For nearly 20 years we've embedded engineers inside the teams of...

We're hiring a React Native engineer to build a mobile app for a large regulated UK organisation. It's used at scale, so dependable, accessible mobile matters a lot here. What you'll do: Build and ship a cross-platform app in React Native and TypeScript. Deliver for both iOS and Android. Keep accessibility front of mind throughout. Work with backend and design to ship features end to end. What we're looking for: Strong React Native and TypeScript. Proven experience shipping apps to the App Store and Play Store. Good grasp of mobile accessibility. Solid understanding of mobile performance and testing. Comfortable using AI-assisted development tools like GitHub Copilot as part of your everyday workflow. Bonus points for financial services or regulated-app experience. About hedgehog lab: We're hedgehog lab, a digital product and engineering consultancy. For nearly 20 years we've...

Applied AI Engineer - Financial Services AI - Outside IR35 - Remote The Applied AI Engineer will be responsible for designing and deploying production AI applications for investment, credit and portfolio management teams, building enterprise LLM solutions that integrate internal and third-party data to support AI-driven financial workflows. Applied AI Engineer - Key Skills: - Proven experience building production AI applications using LLMs within Financial Services (Investment Management, Investment Banking, Asset Management, Hedge Funds, Private Credit or similar). - Must have strong understanding of RAG architectures, AI agents and enterprise AI systems, including document parsing, chunking, retrieval, re-ranking and orchestration. - Strong Python experience building production AI applications, Back End services and APIs. - Strong Azure experience, including Azure OpenAI and cloud-native AI services. - Experience deploying production AI systems using Kubernetes,...

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,...

Who are OnCommerce?   OnCommerce is a global selling platform that powers a growing network of retail channels, including: OnBuy - The only marketplace in the world to give customers instant Cashback on everything easyShop - An all-new marketplace created in collaboration with the easy® family of brands Comet - The iconic UK tech brand making its return later this year   OnCommerce is growing fast, launching new brands and scaling to power the future of ecommerce.   Be Part of the Story OnCommerce is constantly evolving. Everyone here plays a hands-on role in shaping what comes next, building brands that make an impact across global markets. There’s no red tape or rigid corporate structure; just smart people taking ownership and figuring things out as we build something big together. The pace is fast, priorities shift, things aren’t always perfectly set up, and you’ll often need to get stuck in and...

Join a central government organisation where your Oracle Cloud expertise will maintain critical national infrastructure in a high-security environment. Salary: £550 - 575 per day + Outside IR35 Job Specification: DV Cleared-Oracle Cloud Engineer Employment Type: Full-Time Location: Milton Keynes UK-based working required, 3 days on site in MK Clearance Required: DV (Developed Vetting) Position Type: Contract (Outside IR-35) The Role A central government organisation is seeking to recruit a DV cleared Oracle Cloud Engineer on an initial 3 month contract basis, 2-3 days per week in Milton Keynes (high likelihood of extension), paying £550/day outside IR35 to start asap (potential for increase in rate). Under the applications sits an OCI estate of production and non-production environments, and this role owns keeping that estate healthy, current, recoverable and affordable. Builds are scripted, restores are rehearsed, patching runs to a clock, and there is a...

Join a central government organisation where your Oracle Cloud expertise will maintain critical national infrastructure in a high-security environment. Salary: £550 - 575 per day + Outside IR35 Job Specification: DV Cleared-Oracle Cloud Engineer Employment Type: Full-Time Location: Milton Keynes UK-based working required, 3 days on site in MK Clearance Required: DV (Developed Vetting) Position Type: Contract (Outside IR-35) The Role A central government organisation is seeking to recruit a DV cleared Oracle Cloud Engineer on an initial 3 month contract basis, 2-3 days per week in Milton Keynes (high likelihood of extension), paying £550/day outside IR35 to start asap (potential for increase in rate). Under the applications sits an OCI estate of production and non-production environments, and this role owns keeping that estate healthy, current, recoverable and affordable. Builds are scripted, restores are rehearsed,...

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...

Technical Lead/Senior Full Stack Developer | .NET, SQL, GDS The Rate - £550 per day IR35 Status - Outside IR35 The Location - UK (remote) The Working Pattern - Remote Duration - August 2026 to late March 2027 About the Client Digital Skills are working with a niche data and public sector technology consultancy supporting a consortium of UK Local Authorities. The programme centres on scaling a secure data platform used for national reporting, policy development and cross-authority data standardisation. About the Role This is a blended Technical Lead and Senior Full Stack Developer role, combining hands-on engineering with delivery leadership. You will own technical direction while actively contributing to development, leading the platform through public Beta in line with GDS standards. Responsibilities A key responsibility for this role is to lead the project as it undergoes GDS Service Assessment. Lead delivery of a GDS-aligned digital service...

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 avoid missing out! 

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...

hackajob is collaborating with Solirius Reply to connect them with exceptional professionals for this role. Front End Engineer - React, Next.js, JavaScript (Remote, Contract - Outside IR35) The Role We are looking for an experienced Front End Engineer on an Outside IR35 contract basis to deliver user-centric digital services for our public sector clients. This is a fully remote role focused on building accessible, performant web applications aligned with GDS standards. You will work within multidisciplinary agile teams to produce production-quality front-end solutions that make a real difference to public services. Key Responsibilities Develop and maintain front-end applications using React and Next.js Build accessible, responsive interfaces compliant with WCAG 2.2 AA and GDS Design System Collaborate with designers, product owners, and back-end engineers in Agile delivery teams Write clean, testable JavaScript/TypeScript with comprehensive unit and integration...

Quality Assurance Engineer 6-month contract Remote Working (UK-based) Outside IR35 £350 to £375 per day Start - ASAP The Opportunity: We are supporting a confidential programme for a major central government project (Government Digital Services) and are seeking an experienced Quality Assurance Engineer to join a multidisciplinary Agile delivery team working on the development of modern, cloud-based data platforms and user-facing digital services. This role is ideally suited to a QA professional with experience testing data-driven systems, validating end-to-end data pipelines and assuring the quality of applications that consume and present complex datasets. You'll work closely with Product Owners, Data Engineers, Developers and Business Analysts to ensure that data is processed accurately, integrations perform reliably and end users receive high-quality, trusted information. Experience with cloud-based data platforms, REST APIs and geospatial...