30 backend engineer jobs found

Role: Backend Engineer (Java/C#/.NET) Location: (Hybrid 2-3 days a week onsite) Status: Outside IR35 Rate: Neg Duration: Initial 6 months (Extensions due) Role We're looking for a Backend Engineer with experience in Java, C#, or .NET to help build and maintain the systems behind our products. You'll work with a mix of relational and NoSQL databases and play a key role in delivering reliable, well-designed RESTful APIs. What you'll do: Design, build, and maintain RESTful APIs Work with relational and/or NoSQL databases to store and manage data efficiently Write clean, testable, production-ready code in Java, C#, or .NET Collaborate with the wider engineering team on system design and delivery What we're looking for: Experience with Java, C#, or .NET Practical experience building RESTful APIs Familiarity with relational and/or NoSQL databases

Synapri are working with a LegalTech business looking to hire a Backend Engineer to support on an initial 3-6 month contract project. The contractor hired will help design and build a high volume, scalable Back End platform which interfaces with an exciting new AI product. Core technology covers C#, API Integration, SQL within an AWS environment. This is an exciting role for someone contribute to approach in addition to build and delivery. Rate: Outside IR35 Location: London, remote with Adhoc travel into the office Duration: Initial 3 months with a view to extend Experience required: Experience Backend developer with at least 5 years of commercial C#/.NET experience Experience with distributed systems, queues, asynchronous processing and background workers Previous experience working within a Legal/Legal technology business or worked with different Document management platforms Good knowledge PostgreSQL or SQL Server. Comfortable designing and consuming REST...

Position: Backend Python Engineer Pay rate: £400 to £450 Duration: 12 months duration Location: London, Redman Place - onsite 3 days a week. IR35: Outside IR35 Backend Engineer with strong FastAPI and microservices experience, ideally gained in cloud-native environments. Exposure to AI/GenAI products is highly desirable. Candidates should be comfortable owning technical solutions, contributing to architecture, mentoring others, and working within Agile product teams. Experience with PostgreSQL, Docker, GitHub Actions, and modern Back End engineering practices is essential. Essential Skills Strong Python development experience (FastAPI, Pydantic, SQLAlchemy, Pytest). Experience with PostgreSQL, Docker, Git/GitHub, GitHub Actions, and microservices. Knowledge of Pandas, NumPy, OpenTelemetry, and cloud-native development. Strong communication, problem-solving, and stakeholder management skills. Ability to take ownership and thrive in a fast-moving environment....

Role: Backend Kotlin Engineer Location: Manchester Status: Outside IR35 Rate: Neg Duration: Initial 3 months (Extensions due) Role We're hiring a Backend Engineer with strong Kotlin experience to join our team. This role offers full flexibility - work from our London or Manchester office, or remotely, whichever suits you best. What you'll do: Build and maintain Back End services and APIs using Kotlin Write clean, well-tested, maintainable code Work closely with product and engineering teams to deliver new features Participate in code reviews and contribute to engineering best practices What we're looking for: Solid experience developing Back End applications in Kotlin Good understanding of Back End architecture and API design Ability to work independently in a remote or hybrid environment Strong communication skills, especially important for remote collaboration

Role: Backend Kotlin Engineer Location: London Status: Outside IR35 Rate: Neg Duration: Initial 3 months (Extensions due) Role We're hiring a Backend Engineer with strong Kotlin experience to join our team. This role offers full flexibility - work from our London or Manchester office, or remotely, whichever suits you best. What you'll do: Build and maintain Back End services and APIs using Kotlin Write clean, well-tested, maintainable code Work closely with product and engineering teams to deliver new features Participate in code reviews and contribute to engineering best practices What we're looking for: Solid experience developing Back End applications in Kotlin Good understanding of Back End architecture and API design Ability to work independently in a remote or hybrid environment Strong communication skills, especially important for remote collaboration

Leading eCommerce client now requires a hands-on Senior Backend Engineer to join their Platform Team and contribute towards the design and development of high volume, scalable and resilient ecommerce platforms.   The role: Building backend 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. e.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...

Role: Senior Java Engineer Location: London or Manchester - Hybrid (2-3 days/week in office) Rate: Neg Status: Outside Ir35 Length: Initial 6 months Role We're looking for a Senior Backend Engineer to join our clients engineering team, working primarily in Java to design, build, and scale Back End systems that power our products. You'll take ownership of key services, mentor other engineers, and help shape our technical direction. What you'll do: Design and build robust, scalable Back End services in Java Deploy and manage infrastructure on AWS Collaborate closely with cross-functional teams to ship high-quality features Contribute to architectural decisions and technical strategy Mentor junior and mid-level engineers What we're looking for: Strong, proven experience as a Back End engineer working in Java Solid hands-on experience with AWS Experience with Node.js is a plus A collaborative mindset and a track record of...

London | Hybrid | Outside IR35 | 6-month initial contract   Are you a Senior Backend Engineer with strong TypeScript, C# and AI-assisted development experience, looking for the opportunity to work on something genuinely new?   Our client is building a new digital delivery platform and is looking for a Senior Backend Engineer to join a small, high-performing engineering team.   This is a contract position, initially for 6 months with potential for extension. The role is outside IR35, based in London on a hybrid basis, and the client is looking for someone to start as soon as possible.   This is a TypeScript-forward backend role , with genuine hands-on C#/.NET work. The successful engineer will build new services and BFF endpoints in TypeScript, whilst also working with existing C#/.NET services to understand and faithfully port established business logic into the new platform. A key part of the role will be agentic...

🚀 Contract Front-End Developer – React / TypeScript 📍 Manchester – Hybrid (2 days per week onsite) 💰 £440 per day 📅 6-month initial contract ✅ Outside IR35   We're working with a major technology-led organisation looking for an experienced Front-End Developer to join a high-performing engineering team. You'll help develop and enhance a high-traffic product used in a fast-moving, transactional environment, delivering new features while ensuring the customer experience remains fast, responsive, reliable and scalable . This is an excellent opportunity for someone who enjoys solving challenging front-end engineering problems where performance, real-time data and user experience are critical.   🛠️ What you'll be doing Building new features across an established, high-traffic web platform Developing modern front-end solutions using React and TypeScript Maintaining and improving clean, scalable and...

Senior C# Engineer – .NET 9/10, AWS Lambda, SQS, SNS – OUTSIDE IR35 £700–£800 per day • Outside IR35 ● 100% Remote • 11 month rolling contract Takeaway: Contribute to the architecture and build of a major greenfield B2B SaaS platform as a deeply senior, hands‑on C# engineer, with heavy emphasis on deep .NET engineering , high‑performance distributed systems , and real‑world AWS serverless delivery . You’ll also have the opportunity to develop hands‑on skills with Claude Code , one of the most advanced AI‑assisted development tools in the industry. Role Overview: You’ll operate as the technical spearhead for a greenfield product build, reporting to the Director of Engineering. Expect deep backend engineering, distributed system design, and high‑quality serverless delivery, plus the chance to adopt modern AI‑assisted development practices as part of your workflow. What You’ll Bring: Senior/Staff‑level backend mastery in C# and .NET 9/10 ,...

Senior C# Engineer – .NET 9/10, AWS Lambda, SQS, SNS – OUTSIDE IR35 £700–£800 per day • Outside IR35 ? 100% Remote • 11 month rolling contract Takeaway: Contribute to the architecture and build of a major greenfield B2B SaaS platform as a deeply senior, hands-on C# engineer, with heavy emphasis on deep .NET engineering , high-performance distributed systems , and real-world AWS serverless delivery . You’ll also have the opportunity to develop hands-on skills with Claude Code , one of the most advanced AI-assisted development tools in the industry. Role Overview: You’ll operate as the technical spearhead for a greenfield product build, reporting to the Director of Engineering. Expect deep backend engineering, distributed system design, and high-quality serverless delivery, plus the chance to adopt modern AI-assisted development practices as part of your workflow. What You’ll Bring: Senior/Staff-level backend mastery in C# and .NET 9/10 , with...

Senior C# / Azure Engineer – £600/day Outside IR35 Contract: Initial contract Rate: Up to £600 per day IR35: Outside IR35 Location: UK – Hybrid Office: 1–2 days per week Start: ASAP / immediately available strongly preferred We are currently recruiting for a Senior C# / Azure Engineer to join an established engineering team of approximately 40 people. This is a hands-on engineering role for someone with strong experience building cloud-based, distributed and event-driven systems using C#, Azure and modern integration technologies. Key Skills Strong commercial experience with C# / .NET Strong Microsoft Azure experience Apache Kafka / event streaming REST APIs and service integration Event-driven architecture Distributed systems Scalable backend services Angular / frontend experience is a nice-to-have The Role You will work as part of a collaborative engineering team, developing and integrating modern cloud-based services...

🚀 Contract Senior Backend Developer – C# / .NET 📍 Central Liverpool – Hybrid, 2 days per week onsite 💰 £380 per day 📅 6-month initial contract ✅ Outside IR35   We're working with a growing technology organisation looking for an experienced Senior Backend Developer to join an established engineering team working on the continued development and modernisation of a large-scale software platform. This will be a backend-focused position , ideal for an experienced C#/.NET Engineer who enjoys building scalable, maintainable and well-tested services , while contributing to engineering standards and modern development practices.   💻 What you'll be doing Designing and developing backend services using C# / .NET Working extensively with SQL Server , including data modelling and performance optimisation Designing and developing RESTful APIs and integrations Building scalable services within a distributed...

Contract Senior Backend Developer - C#/.NET Central Liverpool - Hybrid, 2 days per week onsite £380 per day 6-month initial contract Outside IR35 We're working with a growing technology organisation looking for an experienced Senior Backend Developer to join an established engineering team working on the continued development and modernisation of a large-scale software platform. This will be a Back End-focused position , ideal for an experienced C#/.NET Engineer who enjoys building scalable, maintainable and well-tested services , while contributing to engineering standards and modern development practices. What you'll be doing Designing and developing Back End services using C#/.NET Working extensively with SQL Server , including data modelling and performance optimisation Designing and developing RESTful APIs and integrations Building scalable services within a distributed software environment Writing high-quality unit and automated tests...

About the job Senior Rust Engineer | Outside IR35 | Hybrid If you're a Rust Engineer who enjoys getting under the hood of complex systems and figuring out how things actually work, this could be an interesting one. iO Associates are working with a technology business on a new contract requirement for an experienced Rust Engineer . This isn't a standard backend build. You'll be working with a complex existing system that interacts directly with specialist physical hardware. A key part of the challenge will be reverse engineering the existing system , understanding how the different components interact and helping engineer what comes next. It's the sort of project that needs someone who enjoys investigating difficult problems rather than simply picking up predefined tickets. What you'll be doing Working hands-on with a complex Rust-based system Reverse engineering and understanding existing system behaviour Investigating how the software...

Senior Cloud / DevOps Engineer – Azure & Python - Remote - Outside IR35 We’re looking for a Cloud / DevOps Engineer with strong Azure and Python skills to join our team and help develop, support and scale our B2B Energy platform. The role combines cloud infrastructure, DevOps and Python development/debugging, supporting a range of cloud-hosted products for our clients. You’ll respond to proactive support requirements, troubleshoot and resolve Python backend issues, and provide scaling and reliability support across our platforms. A key part of the role will be helping us mature our cloud offering through the development of Dev Experience tools, reusable cloud modules and improved security controls. You’ll also contribute to areas including: 10+ years commercial IT Engineering/Development experience Azure cloud infrastructure and DevOps Python backend debugging and development CI/CD and automation Disaster Recovery infrastructure patterns Networking modernisation...

Senior Rust Engineer Outside IR35 Hybrid If you're a Rust Engineer who enjoys getting under the hood of complex systems and figuring out how things actually work, this could be an interesting one. iO Associates are working with a technology business on a new contract requirement for an experienced Rust Engineer . This isn't a standard backend build. You'll be working with a complex existing system that interacts directly with specialist physical hardware. A key part of the challenge will be reverse engineering the existing system , understanding how the different components interact and helping engineer what comes next. It's the sort of project that needs someone who enjoys investigating difficult problems rather than simply picking up predefined tickets. What you'll be doing Working hands-on with a complex Rust-based system Reverse engineering and understanding existing system behaviour Investigating how the software interacts with specialist physical hardware...

A public sector organisation is seeking a Senior AWS Platform Engineer to join via a Consultancy to join a strategic programme delivering and evolving a cloud-based occupancy data platform hosted within AWS. The platform ingests and processes data from a range of sources including WiFi networks, IoT sensors and wider property technology systems, generating occupancy insights that support data-driven decision making across a large-scale estate. As the Senior AWS Platform Engineer you will play a key role in the design, build and support of the cloud infrastructure, integrations and automation capabilities that underpin the platform. This is an excellent opportunity for an experienced AWS specialist who enjoys solving complex technical challenges, building cloud-native services and working across platform engineering, DevOps and systems integration. This is an initial contract until May 2027 with potential to be extended, it is one day per week in the office in Central...

Contract Java Engineer | iGaming | Up to £500 per day | Outside IR35 | 6 months | Fully Remote (UK)   We're looking for experienced Java Engineers to join a long-term contract with a product-focused engineering team, building and enhancing scalable, cloud-based applications in the iGaming industry.   This is an excellent opportunity to work on modern Java services within an agile environment, collaborating with talented engineers to deliver high-quality software.   What you'll be doing Designing, developing and maintaining Java applications and microservices. Building scalable, resilient, and high-performing backend systems. Collaborating with cross-functional teams in an agile delivery environment. Writing clean, maintainable, well-tested code. Contributing to technical discussions, architecture and continuous improvement.   What we're looking for Strong commercial experience with Java ....

🚀 Contract Software Developer – C# / Golang / SQL 📍 Manchester – Hybrid (2 days per week onsite) 💰 £500–£520 per day 📅 6-month initial contract ✅ Outside IR35   We're working with a major technology-led organisation looking for an experienced Software Developer to join a high-performing engineering team responsible for a real-time, high-volume transactional platform .   This is a hands-on development role working across backend services, microservices and data-intensive applications in an environment where performance, reliability and scalability are critical . The core technology stack includes C#/.NET, Golang and SQL Server , with the wider environment incorporating Windows applications, microservices, Kafka, Linux and cloud/web technologies.   🛠️ What you'll be doing Developing highly efficient, robust and maintainable applications and backend services Building and enhancing...