51 senior software engineer jobs found

Senior Software Engineer (Contract) 3-Month Engagement | Outside IR35 | Up to £475 per day | Hybrid (London / Ipswich) A rapidly expanding SaaS company is seeking an experienced Senior Software Engineer to support their agile delivery team on an initial 3-month contract. This position offers a strong mix of hands-on development and strategic input, with the opportunity to shape system architecture, influence engineering practices, and contribute directly to product evolution. You’ll play a key role in designing, building, and improving scalable cloud-native applications, while also guiding team members and promoting high standards across the development lifecycle. Core expertise required: Advanced experience with C# and .NET (Framework and Core) Frontend development using TypeScript, HTML, CSS, and either React or Vue Proven track record with AWS, ideally including serverless architectures (e.g., Lambda) Experience with CI/CD pipelines and Infrastructure as...

Senior Software Engineer (Contract) Remote / Oxford (Flexible Hybrid) £500 – £600 per day (Outside IR35) 3–6 Month Contract We’re supporting an innovative deep-tech company developing AI-driven software within a highly complex scientific environment. They’re looking for an experienced Senior Software Engineer to help accelerate backend platform development as they continue to scale. This is a hands-on contract role focused on building robust backend services, APIs, and scalable applications using Python. You’ll work closely with a highly technical engineering team, contributing across architecture, development, and delivery in a fast-paced environment. What They’re Looking For Strong commercial Python experience Experience building APIs and backend services using FastAPI, Flask or similar Strong understanding of scalable software engineering and system design Experience with cloud platforms and containerised environments Comfortable working...

Joining a new project Ideally have worked on Financial Services Projects before (Payments would be great) Fullstack Experience Tech Stack - Kotlin Backend, JS/TS React Frontend Start date ASAP Duration 6 months (Likely to extend) 2/3 days / week in person working (London) Immediate Interviews The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages. Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We've been consistently profitable and have grown responsibly from the beginning. We are based at Old Street in the heart of "tech city" and get thoroughly stuck in with the brilliant community around us. We run several meetups including the hugely popular React...

Joining a new project Ideally have worked on Financial Services Projects before (Payments would be great) Fullstack Experience Tech Stack - Kotlin Backend, JS/TS React Frontend Start date ASAP Duration 6 months (Likely to extend) 2/3 days / week in person working (London) Immediate Interviews   The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages.   Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We've been consistently profitable and have grown responsibly from the beginning.   We are based at Old Street in the heart of ʺtech cityʺ and get thoroughly stuck in with the brilliant community around us. We run...

Joining a new project Ideally have worked on Financial Services Projects before (Payments would be great) Fullstack Experience Tech Stack - Kotlin Backend, JS/TS React Frontend Start date ASAP Duration 6 months (Likely to extend) 2/3 days / week in person working (London) Immediate Interviews   The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages.   Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We've been consistently profitable and have grown responsibly from the beginning.   We are based at Old Street in the heart of "tech city" and get thoroughly stuck in with the brilliant community around...

Senior Software Engineer - Devon Senior Software Engineer - Devon - Outside IR35 - Our client is looking for an experienced Senior Software Developer for a short-term consultancy role with strong Angular and Authentication Specialisation (MSAL). The role will involve the final implementation of the project, including documentation and Automation Flow. If you have the following, please forward your CV:- Angular MSAL - SSO Azure AD Authentication knowledge Strong Development and Implementation knowledge Due to the volume of applications received for positions, it will not be possible to respond to all applications and only applicants who are considered suitable for interview will be contacted. Proactive Appointments Limited operates as an employment agency and employment business and is an equal opportunities organisation We take our obligations to protect your personal data very seriously. Any information provided to us will be processed as detailed in our Privacy...

Senior Software Engineer - Devon Senior Software Engineer - Devon - Outside IR35 Our client is looking for an experienced Senior Software Developer for a short-term consultancy role with strong Angular and Authentication Specialisation (MSAL). The role will involve the final implementation of the project, including documentation and Automation Flow. If you have the following, please forward your CV:- Angular MSAL - SSO Azure AD Authentication knowledge Strong Development and Implementation knowledge Due to the volume of applications received for positions, it will not be possible to respond to all applications and only applicants who are considered suitable for interview will be contacted. Proactive Appointments Limited operates as an employment agency and employment business and is an equal opportunities organisation We take our obligations to protect your personal data very seriously. Any information provided to us will be processed as detailed in...

Senior Software Engineer - Devon Senior Software Engineer - Devon - Outside IR35 - Our client is looking for an experienced Senior Software Developer for a short-term consultancy role with strong Angular and Authentication Specialisation (MSAL). The role will involve the final implementation of the project, including documentation and Automation Flow. If you have the following, please forward your CV:- Angular MSAL - SSO Azure AD Authentication knowledge Strong Development and Implementation knowledge Due to the volume of applications received for positions, it will not be possible to respond to all applications and only applicants who are considered suitable for interview will be contacted. Proactive Appointments Limited operates as an employment agency and employment business and is an equal opportunities organisation We take our obligations to protect your personal data very seriously. Any information provided to us will be...

SC Cleared Senior Software engineer ASAP Start 28/08 finish - strong expectation for extension £450 Outside ir35 Remote Details below Technical Requirements Core Tech Stack Python TypeScript FastAPI PostgreSQL AWS‑hosted environment Additional Useful Experience Familiarity with GDS design framework, (url removed) component libraries, and templating models Experience with authentication integrations (handled via third‑party provider) Exposure to Java (beneficial but not required) Strong automated testing skills — no separate QA function, engineers write their own tests Ability to work with AI tooling (e.g., Copilot); experience guiding best practices is a plus Practices include: Pairing TDD PR reviews Fast‑moving ticket flow No appetite for engineers who over‑discuss or over‑spike — the team values momentum, pragmatism, and delivery focus Team Culture & Expectations Collaborative, supportive, and delivery‑driven High‑profile project → blockers get resolved quickly...

SC Cleared Senior Software engineer ASAP Start 28/08 finish - strong expectation for extension £450 Outside ir35 Remote Details below Technical Requirements Core Tech Stack Python TypeScript FastAPI PostgreSQL AWS hosted environment Additional Useful Experience Familiarity with GDS design framework, GOV.UK component libraries, and templating models Experience with authentication integrations (handled via third party provider) Exposure to Java (beneficial but not required) Strong automated testing skills - no separate QA function, engineers write their own tests Ability to work with AI tooling (eg, Copilot); experience guiding best practices is a plus Practices include: Pairing TDD PR reviews Fast moving ticket flow No appetite for engineers who over discuss or over spike - the team values momentum, pragmatism, and delivery focus Team Culture & Expectations Collaborative, supportive, and delivery driven High profile project blockers get resolved quickly Looking for...

Role: Senior Software Engineer Location: Essex – 5 days a week onsite Pay rate: £600-£700p/d (outside IR35) I’m looking for an experienced C++ engineer looking to work on genuinely complex, mission-critical software. This role is fully on-site, 5 days a week. We're working with a global company based in Essex, seeking an experienced Software Engineer to develop and maintain sophisticated integrated monitoring and automation systems. You'll be working with: • C++ Windows application development (Visual Studio) • Real-time, high-volume data transfer • Serial interfaces and protocols - RS232, RS422, CAN Bus, ModBus, NMEA • Multi-threaded architectures Experience with Qt, TCP/UDP, DirectX/OpenGL or Google Protocol Buffers would be a bonus. This is a hands-on, technically rewarding role with real ownership over what you build - ideal for an engineer who thrives in a specialist, niche environment. Interested? Please reach out to Fintan at TEC...

We are seeking a passionate Software Engineering Manager who will provide technical expertise and operate with excellence. Being creative, curious, and confident, you will be an integral part of our empowered, self-managing, multi-disciplinary engineering teams - designing, building, releasing, and maintaining products. You will play a key role in driving our ambition to create a best-in-class software engineering team, environment, and culture. This is an initial 6 month contract (outside IR35) that requires you to work on client site 3 days a week in London, Paddington. Your key accountabilities will include: • Team Management: Build, mentor, and manage a high-performing software engineering team. Foster a culture of collaboration, innovation, and continuous improvement within the team. Facilitate communication and collaboration among team members. Ensure budgets, people and resource allocation, and workload, balance across projects. • Agile Delivery: Oversee...

Job Description Senior Software Engineer Platform Recruitment Limited Oxford, ENG, GB Job Description Senior Design Engineer Development of real-time machine control software in C#/.NET, integrating lasers, motion control, robotics, and... 19 Dec Senior Data Engineer, Data Platform - Macquarie Group Macquarie Group London, ENG, GB Job Description At Macquarie, our Data Services Team drives innovation by delivering a diverse suite of data products that empower data-driven... 13 Dec Data Platform Engineer - Cyber Data Platform Tesco Technology Welwyn Garden City, ENG, GB Job Description About the role As the Data Platform Engineer in the Cyber Data Platform team, you will contribute to the development and maintenance of... 18 Dec Data Platform Engineer La Fosse London, ENG, GB Job Description Data Platform Engineer London – 4 days per week onsite £120,000 base + 30% bonus + benefits A growing investment organisation is... 19 Dec Senior Data Engineer,...

Senior Software Engineer (Contract) 3-Month Engagement | Outside IR35 | Up to £475 per day | Hybrid (London / Ipswich) A rapidly expanding SaaS company is seeking an experienced Senior Software Engineer to support their agile delivery team on an initial 3-month contract. This position offers a strong mix of hands-on development and strategic input, with the opportunity to shape system architecture, influence engineering practices, and contribute directly to product evolution. You'll play a key role in designing, building, and improving scalable cloud-native applications, while also guiding team members and promoting high standards across the development lifecycle. Core expertise required: Advanced experience with C# and .NET (Framework and Core) Frontend development using TypeScript, HTML, CSS, and either React or Vue Proven track record with AWS, ideally including serverless architectures (e.g., Lambda) Experience with CI/CD pipelines and Infrastructure as Code...

We’re currently hiring for 2 x Senior Product Engineers to join an exciting programme focused on building and evolving a highly secure internal platform operating within a Zero Trust environment. This is a hands-on engineering role suited to someone who enjoys working across product development, frontend engineering, prototyping, and secure platform delivery whilst helping shape and enhance a modern internal product. We’re looking for senior consultants with strong product/software engineering backgrounds who are comfortable contributing across the full development lifecycle in a fast-paced and technically complex environment. ?? Location London / Hybrid ?? Contract 6 Month Contract (With view to extend) Outside IR35 1 x Immediate Start 1 x July Start ?? Technology Environment The core stack includes: C# / .NET / .NET Core TypeScript & JavaScript We are also looking for engineers with broader experience across modern technologies...

Role: Contract Senior Software Engineer Cambridge – onsite 3 days per week £60-£65 per hour (Outside IR35) Duration: 6 months+ Start Date: ASAP The Opportunity Zenovo are supporting a growing and highly successful medical technology company based in Cambridgeshire in their search for an experienced Contract Software Engineer. This is a varied and technically challenging role, where you will contribute across the full software stack, including user applications/UI, embedded systems, and integration with microprocessors and hardware platforms. The role will involve closely working with hardware interfaces, alongside assessing technical feasibility, constraints, and delivery timelines for new functionality and product capabilities. Key Responsibilities Work within the software development lifecycle (SDLC) and engineering change request processes Contribute to product design and development activities Lead development of new applications, including UI, database...

Outside IR35 Backend Software Engineer - MOD/Defence Project, Farnborough, Hybrid, £500-550 per day Contract opportunity for a backend software engineer for a programme involving LLM. This is for a defence consultancy and security clearance (SC) would be needed prior to engagement. Due to the nature of the role, 1-3 days per week in Farnborough is needed. Key skills required Backed development experience (Mid-senior level) Python Data Pipeline Creation and Management API Creation and Integration Database Creation and Integration Working with JSON If you have worked in a security cleared environment, have the active relevant Security Clearance and skilled with backend development - please apply.

Senior Integration Engineer — Critical Infrastructure & OT Location:  Based in either London or Lisburn. Project-based travel between the two — typically a few days at a time, not long-term relocation. UK-wide and occasional European travel on live projects. Engagement : 12-month initial contract, renewable. B2B, weekly GBP, outside IR35. Day rate : £700 – £750 per day, benchmarked deliberately above market. Travel, accommodation and subsistence covered on site-based work. About OKTO: OKTO Integrated Services has spent 33 years delivering complex multi-system integration on projects where the technology has to be invisible and the user experience uncompromising — luxury hospitality (Hilton Waldorf Astoria at Admiralty Arch, The Peninsula London), superprime residential (Mayfair Park Residences, 80 Holland Park, Forbes House) and high-profile corporate clients (Manchester United, Allstate). We are now extending this...

Outside IR35 Backend Software Engineer - MOD/Defence Project, Farnborough, Hybrid, £500-550 per day Contract opportunity for a Back End software engineer for a programme involving LLM. This is for a defence consultancy and security clearance (SC) would be needed prior to engagement. Due to the nature of the role, 1-3 days per week in Farnborough is needed. Key skills required Backed development experience (Mid-senior level) Python Data Pipeline Creation and Management API Creation and Integration Database Creation and Integration Working with JSON If you have worked in a security cleared environment, have the active relevant Security Clearance and skilled with Back End development - please apply.

Senior QA Automation / SDET Engineer (SC + NPPV3 Cleared) Birmingham 6 Month Contract £400-£450/day (Outside IR35)   Hands on   Senior QA Automation Engineer / SDET (Software Development Engineer in Test)  engineer needed with  both SC  and  NPPV3 Security Clearance , plus strong hands-on experience with  JUnit, Cucumber,  and  Selenium WebDriver . 6 Month Rolling Contract based in  Birmingham . Start ASAP in May/June 2026. Hybrid Working – 3 days/week remote (WFH) + 2 days/week working from the office in  Birmingham with occasional travel to Croydon . A chance to work with a leading global IT transformation business specialising in large-scale Government projects: Key skills, experience + duties to include: Extensive hands-on experience with  JUnit, Cucumber,  and  Selenium WebDriver  within  complex enterprise  environments....