13 senior software engineer jobs found in London

Senior Software Engineer - Pricing & Availability (Node/React/.Net) We're supporting a high-traffic global travel and E-commerce platform in its search for a Senior Software Engineer to strengthen its pricing and availability systems. This is a hands-on contract role focused on improving the performance, reliability and scalability of a complex transactional platform processing millions of customer searches across multiple international markets. What you'll be working on: Building and improving pricing, quote-caching and availability services Designing resilient APIs and integration patterns Tackling latency, performance and infrastructure cost challenges Managing the trade-off between pricing freshness and cache efficiency Improving observability through monitoring, tracing and meaningful metrics Working alongside teams responsible for third-party integrations and booking systems Using AI coding tools as part of your day-to-day engineering workflow What...

Senior Software Engineer - Pricing & Availability (Node/React/.Net) We're supporting a high-traffic global travel and e-commerce platform in its search for a Senior Software Engineer to strengthen its pricing and availability systems. This is a hands-on contract role focused on improving the performance, reliability and scalability of a complex transactional platform processing millions of customer searches across multiple international markets. What you'll be working on: • Building and improving pricing, quote-caching and availability services • Designing resilient APIs and integration patterns • Tackling latency, performance and infrastructure cost challenges • Managing the trade-off between pricing freshness and cache efficiency • Improving observability through monitoring, tracing and meaningful metrics • Working alongside teams responsible for third-party integrations and booking systems • Using AI coding tools as...

Senior Software Engineer - Pricing & Availability (Node/React/.Net) We're supporting a high-traffic global travel and E-commerce platform in its search for a Senior Software Engineer to strengthen its pricing and availability systems. This is a hands-on contract role focused on improving the performance, reliability and scalability of a complex transactional platform processing millions of customer searches across multiple international markets. What you'll be working on: Building and improving pricing, quote-caching and availability services Designing resilient APIs and integration patterns Tackling latency, performance and infrastructure cost challenges Managing the trade-off between pricing freshness and cache efficiency Improving observability through monitoring, tracing and meaningful metrics Working alongside teams responsible for third-party integrations and booking systems Using AI coding tools as part of your day-to-day engineering workflow What...

Senior Software Engineer - Outside IR35 - Contract (Energy) About the role We are looking for a Senior Software Engineer (ideally with some Data Engineering experience) to join our client team in the energy trading sector. End date is not certain, but likely to be December 2026 or early Q1 2027. We are looking for experience in the following technologies: Microsoft Azure ecosystem Understanding of networking & security options in Microsoft Azure Infrastructure-as-code (preferably Bicep) Python Experience in the below would also be beneficial: Azure DevOps (pipelines) SQL We generally spend 2 days per week on-site with the client in central London (Monday & Thursday). £500-600 per day outside IR35 Start date: 10/08/2026 End date: December 2026 or early Q1 2027 About Softwire Softwire is a leading UK technology and strategy consultancy. From enterprise to government, we help visionary organisations turn...

Senior/Lead Software Engineer (Java) | Outside IR35 | Hybrid (2 Days Onsite in central London) A large retailer urgently seeks an experienced Senior Software Engineer with extensive Java expertise to take a lead role in the design,development and support of scalable, cloud-native Back End applications. Working within an Agile, DevOps environment, you'll help build high-performance microservices, APIs and event-driven solutions powering a next-generation fulfilment platform used at significant scale. This is an exciting greenfield programme, working alongside engineers, operations and product teams to deliver software that supports critical business operations. Essential Experience Extensive commercial experience developing enterprise applications with Java and Spring Boot Proven track record designing and delivering high-throughput, distributed microservices at scale Strong experience building event-driven architectures using Kafka Expertise with PostgreSQL and...

Senior Mobile Engineer Tech: Kotlin / Swift / Flutter / BLE / NFC Location: Hybrid (Angel, London – 2 - 4 days per month in office) Contract: Outside IR35 (client is exempt) Duration: 8–12 weeks Start: ASAP Rate: £400 - £525 per day The Opportunity: We're partnering with an innovative IoT technology business looking for a Senior Mobile Engineer to lead the build of a brand-new mobile activation app and SDK. This is a greenfield project, replacing a legacy application with a lightweight solution focused on BLE, NFC and background scanning for enterprise customers. You'll own the project from architecture through to delivery, working directly with the Head of Software in a fast-moving, engineering-led environment. What You'll Do: Build a new mobile app and SDK from scratch Develop BLE background scanning and NFC activation Work on both native iOS and native Android and use Flutter for some basic UI screens. Deliver production-ready...

Senior Geospatial Engineer | Outside IR35 | Remote SR2 are looking for a Senior Geospatial Engineer to support the development of scalable spatial data solutions for a cloud-based, data-driven platform. You'll join a cross-functional team, taking ownership of the pipelines and services used to ingest, process, validate, store and publish complex geospatial datasets. The Role You'll design and build robust geospatial workflows capable of handling data at scale. The role combines geospatial engineering, software development and cloud delivery, with the opportunity to influence technical standards, architecture and engineering best practice. Key responsibilities will include: Building pipelines for the ingestion, transformation, validation and publication of spatial data Developing scalable geospatial services and processing workflows Working with traditional and cloud-native spatial formats Consuming and publishing data through REST and OGC APIs Optimising spatial...

Azure | Databricks | SQL | Outside IR35 | Hybrid THE COMPANY We 're partnering with a global mining organisation that is investing heavily in the evolution of its enterprise data platform. Following significant growth and a wider transformation programme, they 're looking to bring in an experienced Senior Data Engineer to strengthen the technical capability of the team and support the delivery of several high-profile data initiatives. This is a business that places real value on engineering best practice and is looking for someone who can provide immediate technical expertise, influence engineering standards through delivery and help solve complex data engineering challenges across the organisation. THE ROLE This is a hands-on Senior Data Engineering contract where you 'll operate as a senior individual contributor within a highly collaborative team. Rather than leading people, you 'll lead technically, owning complex engineering problems, partnering with...

🚨 Active DV Cleared Full Stack Engineers 🚨 I'm working with a leading UK defence client on a major AI programme and am looking to speak with experienced DV Cleared Full Stack Engineers for a long-term contract opportunity. The Role 12-month contract Outside IR35 £500–£600 per day London (4 days onsite) You'll be joining a multidisciplinary engineering team delivering secure, mission-critical software on one of the UK's most exciting defence programmes. We're keen to hear from engineers with experience in areas such as: Python Java React MongoDB AI / Machine Learning Kubernetes VMware AWS or Azure Essential: Active UK DV Clearance Happy to work onsite in London four days per week If you're looking for your next contract within the defence sector, I'd be happy to tell you more.

AI SOFTWARE ENGINEER - DV CLEARED BRAND NEW OUTSIDE IR35 CONTRACT OPPORTUNITY AVAILABLE WITH A LEADING NATIONAL SECURITY CONSULTANCY FOR AN AI SOFTWARE ENGINEER Contract opportunity for an AI Software Engineer Outside IR35 Day rate up to £650 Hybrid role - London Must hold active UKSV DV clearance To apply please email or call WHO WE ARE? We are working with a specialist consultancy delivering cutting-edge AI and software solutions into the UK National Security and Defence sector. Due to continued growth and the expansion of several mission-critical programmes, we are looking for an experienced AI Software Engineer to join a high-performing engineering team in London. WHAT WILL THE AI SOFTWARE ENGINEER BE DOING? You will be designing and building AI-enabled software systems that support complex operational environments. The role will involve developing scalable backend services, integrating machine learning models into production...

Role: Programme Test Lead Rate: £500 p/d Outside IR35 Location: Fully remote Duration: 2 months We are seeking an experienced Programme Test Lead to oversee testing activities across a complex portfolio of technology initiatives. You will be responsible for defining and delivering programme-level test strategies, managing testing risks, coordinating multiple delivery teams, and ensuring high-quality releases across the software delivery lifecycle. Working closely with technology, product, and business stakeholders, you will play a critical role in ensuring delivery excellence and business confidence. Key Responsibilitie sDefine and implement the overall testing strategy, standards, and best practices .Lead, mentor, and develop a team of QA Engineers and Test Leads .Oversee test planning, estimation, execution, and reporting across multiple projects .Ensure appropriate test coverage through functional, regression, integration, performance, and automation...

Full Stack Engineer (LLM/AI) £450 per day | Outside IR35 | 3-6 Month Contract | Hybrid (London) - 2 days onsite | ASAP Start Our trusted EdTech partner, supporting over 600 million users across 100 countries, is looking for an experienced Full Stack Engineer to help deliver the next generation of AI-powered language learning and assessment products. You 'll be a hands-on engineer with strong Python, React, JavaScript/TypeScript and AWS experience, developing scalable cloud-native applications and integrating AI capabilities into production systems. Recent experience developing Chat or Messaging applications within the Education or Learning sector is essential. Key Responsibilities: Develop and maintain scalable full-stack applications using Python, React and AWS. Contribute to technical architecture, solution design and engineering best practice. Build high-quality, secure and performant software through short delivery iterations. Collaborate...

Senior Full Stack Developer AI-Assisted Development Outside IR35 Contract / Central London Avanti Recruitment is working with a growing technology business looking for a Senior Full Stack Developer to help build a suite of modern web applications that are central to its future technology strategy. You 'll be working across React, TypeScript and Node.js, taking ownership of features from concept through to production in a fast-paced, collaborative engineering team. We 're looking for engineers who already use AI coding tools such as Claude Code, Cursor, GitHub Copilot or Codex as part of their everyday development workflow. This isn 't an AI engineering role, it 's about using AI to build great software more effectively. Requirements: Strong commercial experience with React, TypeScript and Node.js Experience building modern web applications or SaaS products Product-focused mindset with strong problem-solving skills Comfortable using...