Senior Platform Engineer

About ENSEK

ENSEK builds the cloud-native SaaS software that’s transforming how energy retailers operate, innovate and manage at scale.

We help retailers lower operating costs, improve billing accuracy for consumers, and enhance customer experience through automation and AI-driven insight, all underpinned by modern, cloud-native architecture.

ENSEK is at an exciting inflection point as we scale at pace towards new international horizons. If you’re driven by solving complex, real-world problems and want to build modern technology that accelerates the global energy transition, you’ll feel right at home with us.

About the role

The Platform Engineer III is an experienced engineer who delivers high-quality, scalable platform services while contributing significantly to infrastructure design, developer experience thinking, and delivery practices. Operating with a high level of autonomy, this role demonstrates strong platform engineering fundamentals, participates in shaping architectural decisions, and supports engineering teams in achieving predictable, value-led delivery. The Platform Engineer III applies advanced capability across Product, Delivery, and Engineering, helping uplift peers and contributing to ENSEK’s platform-first engineering culture.

Key responsibilities:

People & Conduct

• Demonstrate a mature growth mindset, routinely seeking feedback and acting on it to drive improvement.

• Model ownership and accountability, supporting peers in developing the same behaviours.

• Facilitate constructive debate and foster an inclusive, psychologically safe environment.

• Show resilience and adaptability in dynamic and challenging situations

Product

• Understand internal developer needs and platform strategy, using insights to drive technical decisions.

• Use platform metrics and developer feedback to inform conversations, challenge assumptions, and propose improvements.

• Evaluate platform approaches with commercial awareness, identifying cost-efficient infrastructure options.

• Clearly articulate platform value and enable engineering teams to understand and adopt it.

Delivery

• Break down large platform initiatives into incremental, testable slices that unlock early learning and value.

• Contribute to accurate estimation and planning, highlighting risks and dependencies.

• Promote agile ways of working and challenge behaviours that hinder flow and predictability.

• Communicate clearly, simplify complex platform concepts, and produce golden path documentation so teams can self-serve.

Engineering Practices

• Write high-quality, maintainable infrastructure-as-code and platform tooling aligned to ENSEK standards (e.g. Terraform, Crossplane, Helm).

• Contribute to platform architectural discussions; propose cloud-native design options with strong reasoning, including EKS, GitOps, and self-service patterns.

• Apply test-first approaches and contribute to robust testing strategies for platform tooling and infrastructure changes.

• Improve observability, alerting, and operational practices across platform services to ensure reliability for all engineering teams.

• Advocate secure coding and infrastructure practices, including least-privilege access and supply chain hygiene, ensuring compliance with ENSEK’s policy.

Engineering Community

• Share platform knowledge widely, contribute to guilds, and elevate engineering and infrastructure standards.

• Mentor junior engineers, support skill development across the team, and help onboard engineering teams onto platform capabilities and golden path tooling.

• Participate in platform and community improvement initiatives, champion golden path adoption, and uphold ENSEK engineering values.

Experience required:

Key Skills

Product Skills

• Developer Focus: Applies internal engineering team insight to shape platform delivery and technical decisions.

• Insight Driven: Uses platform metrics and developer feedback to challenge assumptions and propose alternatives.

• Commercial Awareness: Understands infrastructure cost implications and identifies value-optimising platform solutions.

Delivery Skills

• Agility: Breaks down complexity; supports effective refinement and estimation.

• Simplicity: Communicates clearly; identifies opportunities to simplify processes and solutions.

Engineering Skills

• Code & IaC: Writes high-quality, well-structured code and infrastructure-as-code; provides meaningful feedback in reviews across Terraform, Crossplane, and GitHub Actions.

• Design: Contributes to platform system design, demonstrating understanding of cloud-native architecture, EKS cluster patterns, and self-service infrastructure.

• Operations: Builds production-ready software and continuously improves operational practices.

• Security & Compliance: Follows and promotes secure development standards.

Soft Skills

• Growth Mindset

• Ownership

• Psychological Safety

• Challenge & Support

• Resilience

Company Benefits

• 25 days’ holiday + bank holidays

• Option to buy or sell 5 extra annual leave days per year

• Vitality Health Insurance, including private healthcare, virtual GP access, mental-health support and wellbeing perks (50% off gym memberships-Virgin Active, Nuffield, PureGym)

• Pensionwith5% matched contribution

• Regular team-wide and company-wide events

• 2 volunteering days per year to give back

• Remote-first working environment with offices in London and Nottingham