Senior Software Engineer

Sanderson; City Of London; On-site; GBP 90,000 - 120,000; Full time

Job summary

Sanderson is seeking a hands-on Senior Software Engineer to join its Technology team and scale an AI-native approach to software development. You will build full-stack apps with C#/.NET, React and TypeScript, develop APIs and microservices, and deploy cloud-native solutions on Azure.

You will also employ AI agents to improve design, testing and delivery and review AI-generated code for quality and security.

Qualifications

• Proven experience in C#/.NET software engineering.
• Full-stack experience with React and TypeScript.
• Experience building APIs, microservices and distributed systems.
• Exposure to CI/CD, Docker, Kubernetes and Terraform/IaC.
• Hands-on AI-native development using tools like Claude Code, GitHub Copilot, or Codex.
• Strong ability to show how AI changes software delivery, not just using AI tools.

Responsibilities

• Build full-stack applications using C#/.NET, React and TypeScript.
• Develop APIs, integrations and microservices.
• Build cloud-native solutions, ideally within Azure.
• Use AI agents across requirements, specifications, coding, testing and delivery.
• Review and validate AI-generated code.
• Contribute to CI/CD, Infrastructure as Code and deployment automation.

Skills

C#/.NET

React/TypeScript

APIs & microservices

CI/CD

AI-native development

Spec-Driven Development

Tools

Docker

Kubernetes

Terraform/IaC

Claude Code / Copilot / Codex

GitHub Copilot

Job description

We’re working with a leading specialty insurance organisation looking for a hands‑on Senior Software Engineer to join its Technology team and help scale an AI‑native approach to software development.

This is not an AI Engineer role focused on building LLM or RAG products. The focus is on experienced software engineers who are already using AI tools and agents to improve how software is designed, built, tested and delivered.

What you'll be doing

• Build full-stack applications using C#/.NET, React and TypeScript
• Develop APIs, integrations and microservices
• Build cloud-native solutions, ideally within Azure
• Use AI agents across requirements, specifications, coding, testing and delivery
• Review and validate AI-generated code
• Contribute to CI/CD, Infrastructure as Code and deployment automation

What we're looking for

• Strong C#/.NET software engineering experience
• Full-stack experience with React and TypeScript
• APIs, microservices and distributed systems experience
• CI/CD, Docker, Kubernetes and Terraform/IaC exposure
• Genuine AI-native development experience using tools such as Claude Code, GitHub Copilot, Codex or similar
• Spec-Driven Development experience is highly desirable

The key requirement is being able to demonstrate how AI has materially changed the way you build and deliver software, rather than simply using ChatGPT or Copilot occasionally.