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