Principal Software Engineer

Overview

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 are hiring multiple Principal Engineers
, 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.

• 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 Dev Ops/Agile practices.
• Managing delivery expectations, timelines and stakeholder relationships.

Essential:

• Strong background as a senior/principal full‑stack engineer (backend + frontend).
• Proficiency in Java, Python, JavaScript/Type Script 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 Dev Ops workflows.

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

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