64 software engineer jobs found

Role: Staff Software Engineer Sector: Life Sciences Location: London Days Onsite: 3 per week Day Rate: £800 Outside IR35 Duration: 4 Months then to extend or go Permanent iO Associates have partnered with Life Science Manufacturing company on their search for a Staff Software Engineer who has a strong background in integrating Medical Devices click apply for full job details

Senior Software Engineer, App Experience, Contract, Outside IR35, Remote, My client, a global hospitality brand, is on the search for a Senior Software Engineer to join a cross-functional App Experience team, helping deliver a best-in-class mobile experience and supporting the rollout of a new feature-flag platform. This role will be predominantly backend work using Node, TypeScript and will involve working closely with API’s, updating / refactoring. What you’ll do Build and enhance backend services powering a widely used customer mobile app Ensure applications are performant, scalable, and secure Participate in agile delivery: code reviews, testing, deployments Integrate enterprise systems into custom-built architecture Tech you’ll work with Node.js, JavaScript, TypeScript, React Automated testing: Jest, React Testing Library, MSW, Maestro CI/CD & cloud tools such as Bitrise, GitHub Actions, Cloud Run, Cloud Build, Terraform React Native and...

Role: Staff Software Engineer Sector: Life Sciences Location: London Days Onsite: 3 per week Day Rate: £800 Outside IR35 Duration: 4 Months then to extend or go Permanent iO Associates have partnered with Life Science Manufacturing company on their search for a Staff Software Engineer who has a strong background in integrating Medical Devices. This role will give you the opportunity to make a real impact in Healthcare and Life Sciences. Essential Requirements Strong .NET / C# background Significant experience integrating and communicating with hardware devices Ability to handle Windows devices, drivers, and communication layers 8+ years of experience at a staff-level , capable of working autonomously Not a web-focused developer; needs to be fully hardware-integration oriented Beneficial Experience gRPC , REST APIs , HTTP Integrating devices in Life Sciences Robotics integration (robotic arms, 6-axis systems) If you're interested, please...

Role: Staff Software Engineer Sector: Life Sciences Location: London Days Onsite: 3 per week Day Rate: £800 Outside IR35 Duration: 4 Months then to extend or go Permanent iO Associates have partnered with Life Science Manufacturing company on their search for a Staff Software Engineer who has a strong background in integrating Medical Devices. This role will give you the opportunity to make a real impact in Healthcare and Life Sciences. Essential Requirements Strong .NET/C# background Significant experience integrating and communicating with hardware devices Ability to handle Windows devices, drivers, and communication layers 8+ years of experience at a staff-level , capable of working autonomously Not a web-focused developer; needs to be fully hardware-integration oriented Beneficial Experience gRPC , REST APIs , HTTP Integrating devices in Life Sciences Robotics integration (robotic arms, 6-axis systems) If you're interested, please respond...

Senior Software Engineer, App Experience, Contract, Outside IR35, Remote, My client, a global hospitality brand, is on the search for a Senior Software Engineer to join a cross-functional App Experience team, helping deliver a best-in class mobile experience and supporting the rollout of a new feature-flag platform. This role will be predominantly Back End work using Node, TypeScript and will involve working closely with API's, updating/refactoring. What you'll do Build and enhance Back End services powering a widely used customer mobile app Ensure applications are performant, scalable, and secure Participate in agile delivery: code reviews, testing, deployments Integrate enterprise systems into custom-built architecture Tech you'll work with Node.js, JavaScript, TypeScript, React Automated testing: Jest, React Testing Library, MSW, Maestro CI/CD & cloud tools such as Bitrise, GitHub Actions, Cloud Run, Cloud Build, Terraform React Native and observability...

Role: Senior Software Engineer - Backend Contract Rate: C.£550 Outside IR35 Per day Location: Leeds - Hybrid (2x days on site) Length: 3-6 months About Us: We are working with a growing, forward-thinking technology company dedicated to building scalable, reliable, and high-performing solutions for our customers click apply for full job details

Role: Senior Software Engineer - Backend Contract Rate: C.£550 Outside IR35 Per day Location: Leeds - Hybrid (2x days on site) Length: 3-6 months About Us: We are working with a growing, forward-thinking technology company dedicated to building scalable, reliable, and high-performing solutions for our customers. Role Overview: As a Senior Software Engineer, you will be responsible for designing, developing, and maintaining server-side applications and services. You'll work closely with cross-functional teams to ensure our systems are performant, secure, and deliver a great user experience. Key Responsibilities: Design, implement, and maintain backend services, APIs, and databases. Collaborate with product managers, frontend engineers, and other stakeholders to deliver features end-to-end. Ensure systems are scalable, reliable, and maintainable. Write clean, testable, and efficient code following best practices. Requirements: Strong programming...

Full-Stack Java Software Engineer (Hybrid Cloud Transformation) I. Role Overview and Engagement This is a critical, hands-on engineering role within a major Financial Services institution focused on accelerating their Cloud Modernization and Migration Strategy . The successful candidate will be integral to developing and deploying enterprise-grade, secure, and scalable microservices within a complex Hybrid Cloud Architecture . Job Title: Full-Stack Java Software Engineer Location: Central London (Hybrid: 2 days onsite) Engagement Model: 1-Month Contract (Outside IR35) to Guaranteed Permanent Conversion Contract Rate: £450/day (during 1-month contract term) Urgency: URGENT – Interviews scheduled this week for ASAP start. Role Type: Highly Hands-on Contributor (Not a Lead position), requiring strong commercial awareness . II. Core Technical Mandate (Mandatory & Non-Negotiable) The engineer must possess recent, demonstrable...

Role: Senior Software Engineer - Backend Contract Rate: C.£550 Outside IR35 Per day Location: Leeds - Hybrid (2x days on site) Length: 3-6 months About Us: We are working with a growing, forward-thinking technology company dedicated to building scalable, reliable, and high-performing solutions for our customers. Role Overview: As a Senior Software Engineer, you will be responsible for designing, developing, and maintaining server-side applications and services. You'll work closely with cross-functional teams to ensure our systems are performant, secure, and deliver a great user experience. Key Responsibilities: Design, implement, and maintain backend services, APIs, and databases. Collaborate with product managers, frontend engineers, and other stakeholders to deliver features end-to-end. Ensure systems are scalable, reliable, and maintainable. Write clean, testable, and efficient code following best practices. Requirements: Strong programming skills...

Role: Senior Software Engineer - Backend Contract Rate: C.£550 Outside IR35 Per day Location: Leeds - Hybrid (2x days on site) Length: 3-6 months About Us: We are working with a growing, forward-thinking technology company dedicated to building scalable, reliable, and high-performing solutions for our customers. Role Overview: As a Senior Software Engineer, you will be responsible for designing, developing, and maintaining Server Side applications and services. You'll work closely with cross-functional teams to ensure our systems are performant, secure, and deliver a great user experience. Key Responsibilities: Design, implement, and maintain Back End services, APIs, and databases. Collaborate with product managers, Front End engineers, and other stakeholders to deliver features end-to-end. Ensure systems are scalable, reliable, and maintainable. Write clean, testable, and efficient code following best practices. Requirements: Strong programming...

Full-Stack Java Software Engineer (Hybrid Cloud Transformation) I. Role Overview and Engagement This is a critical, hands-on engineering role within a major Financial Services institution focused on accelerating their Cloud Modernization and Migration Strategy . The successful candidate will be integral to developing and deploying enterprise-grade, secure, and scalable microservices within a complex Hybrid Cloud Architecture . Job Title: Full-Stack Java Software Engineer Location: Central London (Hybrid: 2 days onsite) Engagement Model: 1-Month Contract (Outside IR35) to Guaranteed Permanent Conversion Contract Rate: £450/day (during 1-month contract term) Urgency: URGENT - Interviews scheduled this week for ASAP start. Role Type: Highly Hands-on Contributor (Not a Lead position), requiring strong commercial awareness . II. Core Technical Mandate (Mandatory & Non-Negotiable) The engineer must possess recent, demonstrable expertise in...

Role: Developer Tech Stack: .NET, C#, AWS, MongoDB IR35 Status: Outside IR35 Day Rate: £400.00 Location: Remote Contract Length: 3 months (highly likely to extend to 6 Months+) Start Date: Immediate We are seeking a Developer to join the agile delivery team supporting the development of a major government digital platform click apply for full job details

Senior Software Developer - 9 Month Contract (Outside IR35) I'm looking for an experienced Senior Developer for a 9 month initial contract for a client of mine in London to start in January 2026. Key Skills for the Senior .NET Developer contract: Experience with modern versions of .NET - Such as .NET 8 and above Excellent knowledge of CI/CD Pipelines / DevOps experience Microservices / Event Driven Architecture Kafka / RabbitMQ The role will involve either developing a greenfield application or upgrading existing legacy code into modern .NET 10. (TBC) Providing you fit all of the above skills criteria and can operate on a hybrid contract in London, please apply below and I will reach out to discuss further.

Senior Rust Engineer (High-Frequency Trading) Contract Length: 6 months (with potential extension) Location: London (4 days per week onsite) Day Rate: Up to £800 (Outside IR35) We’re looking for an experienced Senior Rust Engineer to take ownership of a greenfield high-frequency trading (HFT) platform, leading the development of the execution layer and market-making system. You’ll step into a technical leadership role, driving architecture, improving performance, and ensuring the system is built to world-class standards. If you’ve built ultra-low-latency trading systems before and want to take full responsibility for a new Rust-based platform, this is an opportunity to shape a high-impact project from the ground up. Key Experience Needed Extensive experience designing and developing high-frequency trading systems Strong experience working on Rust with a track record of building low-latency, high-throughput production systems Proven ability to lead the...

Location: Worcester (fully onsite) Duration: 6 month initial contract Rate: £82ph LTD (Outside IR35) Due to the nature of the role, candidates must hold active DV clearance. Role details: Our client, a leading defence and security company, are looking for DV cleared Software/DevOps Engineers to join their team on a contract basis click apply for full job details

Software V&V Engineer: (MBSE / Embedded Systems)Location: AldershotContract Type: Contract (6 months)Pay: £55 Per Hour (Outside IR35) About the Role We’re seeking a highly capable Software Verification & Validation Engineer to design and implement a brand-new automated software test framework for a Model Based Systems Engineering (MBSE) environment. What You’ll Do Design, build, and implement a new automated test framework to validate embedded software against requirements. Lead the verification & validation of a software runtime compiled alongside MBSE-generated code. Perform test execution and hardware integration using ARM-based processors. Prepare and run demonstrations of the MBSE code, runtime, and verification outcomes. Key Skills: Strong embedded C coding Code coverage analysis (GCOV) Unit testing frameworks (CMocka) Hardware integration experience (ARM-class MCUs) Desirable: RTOS (RTEMS or similar) ARM-M7 / Microchip SAM processor...

Front End Software Engineer Start: Jan 2026 Location: Remote (must be EU timezone) Rate: £350-£400 per day (outside IR35) Length: 4 weeks (possible extensions) We’re looking for an experienced Front End Engineer to join a delivery-focused product team on a contract basis. You’ll be working on real-world user interfaces where attention to detail, performance, and maintainable code actually matter. This role suits someone who’s comfortable operating without heavy frameworks when needed, can collaborate closely with design and backend teams, and can drop into an existing codebase without hand-holding. What you’ll be doing Building and maintaining robust, semantic, user-friendly interfaces Working across modern React codebases while also handling non-framework JavaScript and CSS Creating and manipulating SVG assets for scalable, high-quality UI components Collaborating closely with designers and “speaking design” fluently Integrating third-party APIs and...

We have a rare opportunity for a long-term, remote-working senior C# developer contract that falls outside of IR35. About the Role We are seeking a Senior .NET Software Engineer with proven, production-grade experience in C# .NET to lead and deliver critical software components across simulation, IoT integration, and industrial-facing services. You will operate as a hands-on engineer with ownership over architecture, reliability, and long-term technical direction. Required Skills & Experience Minimum 5 years solid C# .Net experience. Experience of architecting systems. Experience with event-driven logic or simulation-style logic (DES, workflows). Strong data modelling abilities and an understanding of how to represent real-world processes in software. Experience with building systems that interact with external devices or services. Excellent communication skills and the ability to work effectively with mechanical, electrical, and controls engineers (ability to pitch...

AI Engineer - Contract (Remote, UK based) - EdTech - 4-6 Months + Possible Extension - £350-375 p/d outside IR35 A UK-based EdTech Start-Up is hiring an experienced contract AI Engineer to help build the next generation of their intelligent assessment systems. Used by awarding bodies and training providers, you'll work across backend services, LLM workflows, evaluation pipelines, and agentic automation. You will deliver scalable AI features that improve the accuracy, consistency, and speed of skills and knowledge evaluation. This role suits someone who enjoys autonomy, works well in a pragmatic environment, and is confident making technical decisions without fully defined specs. You'll design evaluation frameworks, benchmark and tune LLMs, develop APIs, build multimodal pipelines, and contribute to agent-based workflows that combine text, images, video, and semantic analysis. You'll also instrument AI systems with tracing, guardrails, and observability tools (e.g., Langfuse,...

Senior Software Engineer, App Experience, Contract, Outside IR35, Remote, My client, a global hospitality brand, is on the search for a Senior Software Engineer to join a cross-functional App Experience team, helping deliver a best-in-class mobile experience and supporting the rollout of a new feature-flag platform. This role will be predominantly backend work using Node, TypeScript and will involve working closely with API’s, updating / refactoring. What you’ll do Build and enhance backend services powering a widely used customer mobile app Ensure applications are performant, scalable, and secure Participate in agile delivery: code reviews, testing, deployments Integrate enterprise systems into custom-built architecture Tech you’ll work with Node.js, JavaScript, TypeScript, React Automated testing: Jest, React Testing Library, MSW, Maestro CI/CD & cloud tools such as Bitrise, GitHub Actions, Cloud Run, Cloud Build, Terraform React Native and...