Principal / Lead Engineer

Principal / Lead Engineer
Python / Cloud / Terraform / IAM / DevOps / infrastructure-as-a-code IaC

• Rate: Circa 600 - 700 PD (Outside IR35), 6 Months
• Location: London / Hybrid x2 days

We are seeking an experienced Principal / Lead Engineer to join a highly ambitious organisation building a large-scale, mission-critical data and technology platform. This is a unique opportunity to join at the earliest stages of a major programme and play a key role in shaping its technical foundations.

Working closely with the CTO and a small team of senior engineers, you will lead the design and implementation of core infrastructure, establish engineering standards and practices, and make architectural decisions that will have long-term strategic impact.
If you enjoy solving complex technical challenges, influencing technology strategy, and creating robust engineering foundations, this role offers an exceptional opportunity to make a lasting impact.

Role & Responsibilities

Technical Leadership

• Lead the design and implementation of foundational platform infrastructure and engineering capabilities
• Define architectural patterns, engineering standards, and best practices that will guide future development
• Partner closely with the CTO and senior stakeholders to make and document key technical decisions
• Promote secure-by-design principles across all aspects of platform development
• Establish and maintain core engineering tooling, including source control, CI/CD pipelines, infrastructure-as-code, and automated testing frameworks

Platform Engineering

• Design and implement identity and access management solutions with robust authentication and authorisation controls
• Build and manage cloud infrastructure using modern infrastructure-as-code approaches
• Develop audit, workflow, and operational capabilities to support governance and compliance requirements
• Implement networking, monitoring, and security controls for highly secure environments
• Evaluate and integrate appropriate open-source technologies and third-party components
• Contribute to the design and delivery of scalable, resilient, and maintainable distributed systems

Collaboration & Team Development

• Act as a senior technical contributor within a high-performing engineering team
• Mentor engineers and help establish a strong engineering culture as the organisation grows
• Collaborate with product, design, and delivery teams to ensure technology solutions align with business objectives
• Engage with external partners, suppliers, and stakeholders where required

Essential Skills & Experience

• Proven experience leading or making significant contributions to complex distributed, cloud-native, or federated systems
• Strong software engineering expertise in Python, including backend development, automation, and infrastructure tooling
• Hands-on experience with at least one major cloud platform (AWS, Azure, or Google Cloud)
• Strong experience implementing Infrastructure as Code using tools such as Terraform or equivalent
• Experience designing and building authentication and authorisation systems, including modern identity standards and policy-based access controls
• Solid understanding of data storage architectures and the trade-offs between different storage and query patterns
• Experience establishing CI/CD pipelines and engineering best practices within modern software environments
• Ability to work effectively in fast-moving environments with evolving requirements and limited precedent
• Strong communication skills with the ability to explain complex technical concepts to both technical and non-technical audiences

Desirable Skills & Experience

• Experience building secure, highly regulated, or mission-critical platforms
• Familiarity with federated architectures and distributed data access models
• Experience designing solutions with strong governance, auditability, and security requirements
• Knowledge of privacy-preserving technologies and secure computing environments
• Experience evaluating, adopting, or contributing to open-source technologies
• Background working within complex stakeholder environments undergoing significant transformation