Senior Platform Engineer

Company: Willis Towers Watson
Apply for the Senior Platform Engineer
Location: Reigate
Job Description:

Overview

In this role you lead and craft platform infrastructure for a global SaaS team, shaping core ICT capabilities used by market-leading insurance solutions. You will guide engineering practices, contribute hands-on development, and drive architectural decisions that scale across regions and tenants. You’ll collaborate with cross-functional teams to improve maintainability, performance, and delivery velocity, while coaching peers to foster a quality-focused culture. This position offers impact through evolving a robust platform that underpins critical SaaS products.

Pay / Benefits

  • 25 days of annual leave + WTW day
  • Private healthcare
  • Life insurance
  • Group income protection
  • Health assessments
  • Defined contribution pension (matched up to 10%)

Responsibilities

  • Provide technical input, guidance and leadership to the team (code quality, best practices, processes, release management)
  • Assist design and documentation of solutions meeting functional and non-functional requirements
  • Lead by example with hands-on development and best practices for maintainability, testability and performance
  • Participate in sprint planning, daily stand-ups and retrospectives to improve velocity and engineering practices
  • Coach and mentor colleagues to foster a collaborative, quality-focused engineering culture

Key requirements

  • Platform and control-plane engineering for SaaS applications, including stack/environment management and API design
  • Azure stamp-based or scale-unit architectures with multi-region/multi-tenant deployments and stamp lifecycle management
  • Full SaaS development lifecycle experience (requirements, design, implementation, testing, deployment, operations, monitoring)
  • Strong grounding in object-oriented design, SOLID, clean code, code review and Agile delivery
  • Hands-on C# and .NET (Core/6+) backend development
  • Azure cloud and SaaS services experience (Container Apps, AKS, Azure SQL/Cosmos DB, Key Vault, Monitor, Log Analytics)
  • Containerised microservices design/operation, Docker, Kubernetes (AKS), deployment and scaling
  • Infrastructure as Code with OpenTofu or Terraform on Azure; blue/green or canary deployment expertise; drift remediation
  • CI/CD in Azure DevOps (Pipelines, Repos); GitHub and GitHub Actions for workflows
  • Automated testing for infrastructure/platform components; IaC unit/integration tests; policy-as-code (Azure Policy, OPA); IaC linting
  • Security/compliance best practices for cloud/SaaS: least privilege, secret management, private endpoints, secure supply chain
  • Experience with multi-tenant Azure environments, data residency and regional considerations
  • Effective technical leadership and communication, including PoC delivery to diverse audiences
  • Experience with high-volume, low-latency SaaS systems
  • Collaborative
  • Coaching/mentoring
  • Clear communication
  • C#/.NET (Core/6+)
  • Azure cloud services (Container Apps, AKS, Azure Storage, Azure SQL/Cosmos DB)
  • Kubernetes and containerisation (AKS, Docker)

…

Posted: October 1st, 2026