Principal Software Engineer

Principal Engineer - Full-Stack (Java & React)

Up to £130,000 - London - 3 days per week onsite

Harvey Nash have partnered with a global consultancy that helps major organisations modernise their technology, build scalable digital products, and tackle complex engineering challenges. They partner with brands across finance, retail, tech scale-ups and highly regulated environments delivering high-impact solutions at speed.

They're now hiring multiple Principal Engineer's, people who can lead architecture and delivery, advise clients at a senior level, stay hands-on with modern engineering, and shape the technical direction of major projects.

What You'll Be Doing

• Lead the design and implementation of full-stack applications using technologies like Java, Python and Typescript.
• Have experience or exposure to frameworks like Spring, Flask and React.
• Acting as a senior technical consultant, guiding clients through complex engineering decisions.
• Mentoring and uplifting engineering teams, driving best practice across delivery.
• Owning architectural decisions and contributing to long-term technical strategy.
• Ensuring engineering excellence via code reviews, design governance and DevOps/Agile practices.
• Managing delivery expectations, timelines and stakeholder relationships.

What They're Looking For

Essential:

• Strong background as a senior/principal full-stack engineer (Back End + Front End).
• Proficiency in Java, Python, JavaScript/TypeScript or similar.
• Understanding of AI-powered development practices and how they improve the SDLC.
• Expertise in software design patterns, architecture and scalable system design.
• Experience leading engineering teams, coaching developers and influencing technical direction.
• Strong consulting mindset - able to translate complex problems into clear solutions.
• Proven experience in Agile environments and modern DevOps workflows.

Desirable:

• Cloud experience (AWS, Azure or GCP) - including serverless.
• Knowledge of Docker, Kubernetes or other container technology.

What Makes This Opportunity Stand Out

This consultancy offers one of the strongest people-focused benefits packages in the market.

Highlights include:

Work-Life Balance & Time Off

Growth & Development

Health & Wellbeing

Financial Benefits

Discretionary bonus scheme