Principal Engineer in England

Our priority is to match the right person to the right role, and we never want salary to be a barrier to applying. Regardless of your current pay, we will ask about your salary expectations during the application process, and our Talent Team will have an open, honest conversation during the talent call to understand your skills and explore our salary options. If you have questions around salary, please feel free to ask us.

Salary Range: £100,000-£130,000

Location: Chiswick, London - Hybrid

Sponsorship: We are unable to offer sponsorship for this role.

The Role

As a Principal Engineer, you are So Energy's senior technical strategy authority, setting direction across architecture, platform capabilities, engineering standards, and long-term technical investment. You will operate at a company-wide level, shaping how technology enables business outcomes, reduces operational complexity, and scales sustainably. With a particular focus on AI, you will lead So Energy's approach to designing, building, and operating AI-enabled systems across the business. This includes AI implementation in customer operations and contact centres, automation and decision support, internal tooling, and platform capabilities that enable teams to ship faster with higher quality.

This role is not a "big architect" role in isolation. You will work across Engineering, Product, Data, and Operations to create alignment, establish standards, and drive adoption, ensuring So Energy becomes an AI-native organisation where teams can use AI safely, effectively, and confidently. This is also a highly hands-on role. You are expected to stay close to the code and close to delivery, personally leading and delivering high-impact initiatives that materially improve customer outcomes, reduce operational complexity, and shift key business metrics. You will be accountable not just for technical direction, but for ensuring the work lands and moves the needle.

Your Impact

In this high-impact leadership role, you will shape the technical direction of So Energy, ensuring the organisation makes sound, consistent technology decisions that deliver commercial value, improve customer experience, and reduce cost-to-serve. You will:

• Define and drive company-wide technical strategy and architectural direction, ensuring technology choices align to business outcomes, risk posture, and long-term scalability.
• Establish scalable platform patterns, engineering standards, and technical guardrails that enable teams to move fast without sacrificing reliability, security, or quality.
• Lead AI adoption as a strategic capability across the business, driving practical implementation, clear standards, and measurable outcomes.
• Increase AI literacy across Engineering, Product, Operations, and leadership, enabling teams to adopt AI safely and effectively, not just experiment.
• Personally lead and deliver So Energy's highest-impact platform and AI initiatives, ensuring solutions are production-grade, adopted, and materially improve key business metrics.

Why So Energy?

So Energy was created because we knew energy suppliers could be better. Since then, we've grown rapidly but sustainably, with 300,000 customers and over 450 Energists (what we call our people). But we're not done. We're on the road to a net-zero future, and thanks to our partnership with ESB, we're well on the way. We're customer-centric, tech-led, and passionate about sustainability. We're driven to do our best for our customers, for each other, and for our planet. That's why we've built a workplace culture that's supportive, empowering, inclusive, and full of opportunities to grow and make an impact. At So Energy, we take pride in our values-driven culture. We live and breathe by our six core values that guide everything we do: Clear, Honest, Ambitious, Inquisitive, Caring, Sustainable.

What you'll be getting up to in this role:

• Partnering with the Director of Technology to define and deliver So Energy's technical strategy and long-term architecture direction.
• Acting as So Energy's technical strategy authority, shaping platform investment priorities, build vs buy decisions, and technical standards across the business.
• Leading AI as a strategic capability, defining how we design, build, and scale AI solutions across customer operations, automation, and engineering productivity.
• Establishing So Energy's approach to agentic AI, including patterns, guardrails, and production standards (evals, observability, security, privacy, cost controls, and fail-safes).
• Driving AI literacy and adoption across Engineering, Product, and Operations through enablement, playbooks, and hands-on guidance.
• Working closely with the Head of Data to build scalable data platform foundations that enable AI, automation, and high-quality decision-making.
• Mentoring senior engineers and technical leaders, raising the bar for engineering quality, delivery, and technical decision-making.
• Taking personal accountability for delivering high-impact initiatives end-to-end, staying hands-on when needed to ensure work lands and materially improves business outcomes.

You're a great match if:

• Proven experience operating as a Principal Engineer, Technical Architect, or equivalent senior technical authority in a modern product-led organisation.
• Demonstrable experience setting technical direction across multiple teams, balancing autonomy with strong standards and guardrails.
• Deep system design and architecture capability, including designing scalable, resilient, secure distributed systems.
• Strong hands-on engineering fundamentals, including recent experience writing, reviewing, and reasoning about production code.
• Strong stakeholder influence: able to challenge constructively, align senior stakeholders, and create clarity in ambiguity.
• Strong leadership experience mentoring senior engineers and raising the technical bar across the organisation.