Principal Software Engineer

Principal Software Enginee r

Location: London (Hybrid – approx. 1–2 days per month onsite)

Contract: Permanent, Full-time

Package: £80,000–£100,000 + 10% bonus + 10% share options + benefits

Eligibility: UK Security Clearance (SC) eligibility required

The Opportunity

We’re working with a specialist cloud and platform engineering consultancy that partners with organisations across regulated and public-sector environments to modernise how software is built and operated.

The business is expanding its software engineering capability and is hiring a Principal Software Engineer to play a key role in shaping technical direction, delivery standards, and engineering best practices across multiple engagements.

This is a hands-on leadership role suited to an experienced engineer who enjoys operating across architecture, design, and delivery, while mentoring teams and working closely with stakeholders.

As a Principal Software Engineer, you will:

• Lead the design and delivery of modern, scalable, cloud-native software systems
• Shape architecture, service boundaries, and system decomposition using best-practice approaches
• Work hands-on across the stack, with a strong focus on React-based applications
• Guide teams on testing strategy, automation, and developer productivity
• Support customers in reducing technical debt and improving long-term maintainability
• Collaborate closely with cloud and platform engineering teams to deliver end-to-end solutions
• Act as a senior technical advisor, supporting decision-making and technical trade-offs
• Contribute to shared engineering standards, patterns, and ways of working

About You

You’re a senior/principal-level engineer with strong architectural judgement and a consulting mindset. You’re comfortable leading technical conversations, influencing delivery decisions, and working directly with customers.

You’ll bring:

• Strong experience with Domain-Driven Design (DDD) and modern system decomposition
• Proven delivery of microservice-based architectures
• Deep hands-on experience with Java/Spring and React
• Experience improving engineering effectiveness through testing strategy and automation
• Exposure to cloud-native environments (AWS preferred)
• Confidence mentoring engineers and leading technical discussions
• Comfort working with stakeholders in regulated environments
• Eligibility for UK Security Clearance (British citizenship required)

Core technologies:

• Java / Spring
• React / JavaScript
• SQL / NoSQL databases
• Docker / Kubernetes
• AWS
• Playwright
• GitLab, Maven

Nice to have:

• GovUK UI Framework
• Azure or GCP
• .NET

Benefits

• Flexible working with core hours
• Hybrid working model
• 25 days holiday + bank holidays + birthday off
• Enhanced parental leave
• Private healthcare (with family cover options)
• Pension with salary sacrifice
• Mental health and wellbeing support
• Cycle to Work & Electric Car schemes