Principal Software Engineer (Java / React) in London

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Job DescriptionPrincipal Software Engineer

Tech: Java / Spring / SQL / React / JavaScript / Docker / Kubernetes / AWS
Remote + Hybrid (1 day a week onsite negotiate)  
£80,000 - £100,000 + bonus and shares

The Opportunity
We are VERY excited about this opportunity. We’ve been working with this client for years and every candidate we have ever placed with them have loved it there. Contractors go perm with them, and permies stay for years. If you are considering a career move, this is (almost certainly) the client for you.
We (SR2) have partnered with this highly regarded cloud and software engineering consultancy that helps organisations modernise how they design, build, and run software. Their teams work at the intersection of software engineering, cloud platforms, and developer experience, supporting customers to reduce technical debt, improve delivery maturity, and build systems that scale sustainably over time. Projects span both public and private sector environments, often tackling complex, high-impact problems where quality, security, and reliability really matter.

They’re now looking for a Principal Software Engineer to provide senior technical leadership across multiple delivery engagements and to help shape how modern software is built, evolved, and maintained.

You’ll join as a founding engineer within this capability, with the opportunity to shape the technical direction and help build out the team over time. This is a chance to play a meaningful role in a growing, mid-sized organisation - where your decisions, leadership, and engineering standards will have a visible and lasting impact on both the platform and the people around you.
 
The Role
This is a hands-on leadership role for an experienced engineer who enjoys operating across architecture, design, and delivery.
You’ll work closely with engineers, delivery leads, and platform teams to:

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• Lead the design and evolution of modern, scalable software systems

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• Influence architectural direction and technical decision-making

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• Support early-stage solution design and complex delivery challenges

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• Mentor engineers and raise the technical bar across teams

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Alongside client work, you’ll also contribute to the organisation’s wider engineering capability, helping define standards, patterns, and best practices that are reused across engagements.
This role suits someone who enjoys technical depth, pragmatic decision-making, and collaborating closely with customers rather than working in isolation.
 
About You
You’re a senior engineer with strong architectural judgement and a passion for building well-designed, maintainable systems. You’re comfortable leading technically, influencing others, and working in environments where collaboration and communication matter as much as code.

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• Deep hands-on experience with Java/Spring and full-stack development\n

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• Strong experience with Domain-Driven Design (DDD) and modern system decomposition

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• Proven delivery of microservice-based architectures

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• Strong React experience and modern frontend practices

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• Experience improving engineering effectiveness through testing, automation, and tooling

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• Exposure to AI-assisted development to improve quality and productivity

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• Confidence mentoring engineers and leading technical discussions

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• A consulting mindset — able to translate business problems into practical technical solutions

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• Experience in regulated or public sector environments

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Tech:

• Java / Spring / SQL / React / JavaScript / HTML / CSS / XML / Playwright / Docker / Kubernetes / Maven / GitLab / AWS

 
Why This Role and Company?

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• Flexibility with a company that genuinely care about their employees

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• Influence architecture and engineering direction at a senior level

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• Work on meaningful, technically challenging systems

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• Balance hands-on engineering with leadership and mentoring

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• Join a consultancy that genuinely invests in engineering quality, not just delivery speed

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• Competitive package including bonus and share options

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Please apply with a copy of your CV and Emma from SR2 will contact potential candidates regarding next steps.

If you are interested in applying for this job please press the Apply Button and follow the application process. Energy Jobline wishes you the very best of luck in your next career move.