Principal Software Engineer jobs in London

About The Role Deadline for applications: 11:59pm on 31st October 2025 Applying for this role is straight forward Scroll down and click on Apply to be considered for this position. Were looking for a Principal Software Engineer to shape the technical direction of high-profile projects and lead the delivery of modern, scalable software. xujxxms We use technology to create impactful,...

You will work closely with subject matter experts and senior stakeholders on high-impact programmes spanning modelling and simulation, autonomy, geospatial systems, synthetic environments and digital twins.

You will remain deeply technical while setting direction, leading teams and acting as the technical authority across projects.

Job Description I’m supporting an early-stage AI startup building genuinely transformational tooling for some of the most document-heavy industries out there. They’re now looking for a Staff or Principal Software Engineer who wants to design and ship AI-driven product capabilities end-to-end, from the first customer conversation all the way to production rollout and adoption. What you’ll be...

Principal Software Engineer Fully Remote | Permanent | £85,000 - £115,000 Harrington Starr has partnered with a leading Global Payments Technology company who are seeking to hire a Principal Software Engineer to join their senior engineering leadership team. This is a rare opportunity to combine hands-on development with strategic influence, guiding architecture decisions and shaping the...

Principal Software Engineer .NET £90,000-£110,000 Remote (UK) Do you thrive on building scalable solutions that power commerce worldwide? We're partnering with a rapidly expanding global payment platform fresh off a transformative acquisition. They're engineering a robust, merchant-centric ecosystem built on quality, resilience, and scale - and they need exceptional .NET Software Engineers to...

Senior/Principal Software Engineer (PHP, MySQL, AWS) Join to apply for the Senior/Principal Software Engineer (PHP, MySQL, AWS) role at Arrive. We've signed up to an ambitious journey. Join us! As Arrive, we guide customers and communities towards brighter futures and more livable cities. It isn't a challenge just anyone could take on. Luckily, we have something to help us make it happen. Our...

Overview We offer a flexible working policy that supports a healthy balance between personal and professional wellbeing. This role requires in-office presence on Tuesdays & Thursdays to collaborate, connect, and learn from peers while maintaining flexibility for meaningful work-life balance. Being an AI Principal Software Engineer at iManage Means... Being an AI Principal Software Engineer at...

You will architect and implement critical solutions that power real-time trading decisions, while mentoring teams and driving client relationships at the highest level.

You will go toe-to-toe with senior engineering stakeholders in fast-paced trading environments, influencing architecture, operating models, and data strategy.

A leading global biopharma company is seeking a Senior Principal Software Engineer in London. The ideal candidate will have a robust background in software development, data engineering, and AI/ML technologies. The role involves architecting cloud-native applications, building scalable data pipelines, and integrating AI models into production environments. This position requires proficiency in...

A leading biopharmaceutical firm in London seeks a Senior Principal Software Engineer to design cloud-native applications and maintain data pipelines. This hands-on role involves writing production-grade code using Python and Azure services, and integrating AI/ML capabilities into applications. The ideal candidate will have a Bachelor's degree in Computer Science, extensive experience with...

You will help them stay ahead of the curve by solving both technical and sociotechnical problems. You would be joining a squad of Principal engineers with different expertise that serves as a centre of excellence to the 16+ engineering teams in the wider engineering function.

Job Description Senior Backend Engineer | London | £100,000 - £160,000 | Python | FastAPI | Systems Location: London based - hybrid Salary: £100,000 - £160,000 + equity Tech Stack: - Backend: Python (FastAPI) - Cursor, Claude Code - AWS Are you a backend engineer who cares more about building robust systems than chasing AI hype? We are working with a recently funded Series A technology...

You will interact with architects, software and data engineers, AI/ML modelers, product owners as well as other team members across R&D.

You will actively participate in creating technical solutions, designs, implementations and participate in the relentless improvement of R&D Tech systems in alignment with agile and DevOps principles.

Senior Backend Engineer | London | £100,000 - £160,000 | Python | FastAPI | Systems Location: London based - hybrid Salary: £100,000 - £160,000 + equity You can get further details about the nature of this opening, and what is expected from applicants, by reading the below. Tech Stack: - Backend: Python (FastAPI) - Cursor, Claude Code - AWS Are you a backend engineer who cares more about...

Job Description Senior Backend Engineer | London | £100,000 - £160,000 | Python | FastAPI | Systems Location: London based - hybrid Salary: £100,000 - £160,000 + equity Tech Stack: - Backend: Python (FastAPI) - Cursor, Claude Code - AWS Are you a backend engineer who cares more about building robust systems than chasing AI hype? We are working with a recently funded Series A technology...

You will help them stay ahead of the curve by solving both technical and sociotechnical problems. You would be joining a squad of Principal engineers with different expertise that serves as a centre of excellence to the 16+ engineering teams in the wider engineering function.

About The Role Deadline for applications: 11:59pm on 31st October 2025 Applying for this role is straight forward Scroll down and click on Apply to be considered for this position.Were looking for a Principal Software Engineer to shape the technical direction of high-profile projects and lead the delivery of modern, scalable software. xbpsjkuWe use technology to create impactful, human-centred...

A global healthcare leader in London is seeking a skilled software engineer to join our R&D Technology team. The ideal candidate will have significant experience in Python programming, cloud-native application architecture, and data engineering. The role includes designing scalable solutions on Azure, optimizing performance, and collaborating cross-functionally. This position offers the...

Job Description I’m supporting an early-stage AI startup building genuinely transformational tooling for some of the most document-heavy industries out there. They’re now looking for a Staff or Principal Software Engineer who wants to design and ship AI-driven product capabilities end-to-end, from the first customer conversation all the way to production rollout and adoption. What you’ll be...

Senior Backend Engineer | London | £100,000 - £160,000 | Python | FastAPI | Systems Location: London based - hybrid Tech Stack: Python (FastAPI) AWS Are you a backend engineer who cares more about building robust systems than chasing AI hype? We are working with a recently funded Series A technology company building AI powered automation for real world, critical workflows. Their platform captures...