Lead Software Engineer – C#/.NET, React & AI

djr; Wimbledon; On-site; GBP 90,000 - 130,000; Full time

Job summary

djr is seeking a highly experienced Software Engineer to influence architecture and engineering standards across a major SaaS platform. You will work with C#/.NET on backend services and TypeScript on frontend, with a focus on secure, modular, scalable designs and responsible AI-enabled development.

You'll mentor engineers, own production reliability, and drive CI/CD, observability and modern practices across the stack while delivering impact in a global technology environment.

Qualifications

• Senior Software Engineer with complex production systems experience.
• Able to influence architecture and engineering standards across an org.
• Comfortable mentoring experienced developers and shaping AI-assisted engineering.

Responsibilities

• Shape security, resilience and maintainability across backend, APIs and frontend services.
• Influence architecture and engineering standards; drive modern engineering practices.
• Mentor engineers and promote production ownership, reliability and observability.
• Explore AI-assisted development with responsible governance, validation and human oversight.

Skills

C#/.NET

TypeScript

React

Angular

Vue

APIs

AWS

SQL Server

PostgreSQL

Docker

Kubernetes

CI/CD

Observability

Technical leadership

Tools

OpenAI tools

LLM integration

Job description

We’re partnering with an established global technology business looking for a highly experienced Software Engineer to help shape the next generation of a major SaaS platform.

This is for someone who still wants to engineer.

Not a people-management position disguised as a technical role. Not endless architecture meetings. And not a legacy .NET position with an “AI” badge added to the advert.

You’ll operate at the senior end of a modern Product Engineering organisation – solving difficult technical problems, influencing architecture and engineering standards, mentoring experienced developers and helping determine how AI-assisted engineering should be used responsibly across the software lifecycle.

The opportunity

You’ll have significant influence over how secure, resilient and maintainable software is designed and delivered across backend services, APIs, frontend applications and distributed systems.

You’ll challenge existing approaches, help evolve systems towards more modular and independently deployable components, and make pragmatic architectural decisions based on genuine business and engineering outcomes.

Crucially, AI is becoming part of the engineering environment rather than sitting in a separate innovation team.

You’ll help explore how coding agents and AI-assisted development can improve analysis, design, implementation, testing, debugging and delivery – while ensuring engineering judgement, security and quality remain firmly in the hands of the engineers.

Where AI enters the product itself, you’ll help establish the controls required to take it into production responsibly, including validation, guardrails, permissions, observability, evaluation, failure behaviour and appropriate human oversight.

What you’ll bring

You’ll be an accomplished Software Engineer who has designed and delivered complex production systems and is comfortable having genuine technical influence across an engineering organisation.

We’re particularly interested in experience across:

• C#/.NET and modern backend engineering
• TypeScript with React, Angular or Vue
• APIs, distributed systems and service-based architectures
• AWS or another major cloud platform
• SQL Server/PostgreSQL and relational data modelling
• Docker, Kubernetes and Infrastructure as Code
• Event-driven architecture
• CI/CD, automated testing and modern engineering practices
• Production ownership, reliability and observability
• Technical leadership and mentoring other engineers

The underlying brief prioritises strong C#/.NET experience but can consider engineers from another modern backend language who are willing to work primarily within the Microsoft stack.

Where AI comes in

You do not need to be an AI Engineer.

We're looking for an exceptional Software Engineer who understands that the way software is built is changing and wants to be at the forefront of that change.

Experience with technologies or concepts such as OpenAI, Anthropic Claude, Amazon Bedrock, LLM APIs, coding agents, structured outputs, tool calling, RAG, semantic search, model routing or AI evaluation would be highly relevant.

However, we're far more interested in engineering principles, judgement and learning ability than whether you've worked with a particular AI framework.

Why consider it?

This is a chance to have genuine technical influence without moving away from engineering.

You'll be working on a substantial global SaaS product, helping modernise architecture, improving how engineering teams build and ship software, mentoring strong developers and influencing how an established technology organisation adopts AI in production.

You get the scale and complexity of an established global technology business, combined with an engineering environment that is actively changing how it builds products.

If you're a senior engineer who wants your next move to be about technical ownership, modern

Product Engineering and where AI takes software development next, this is worth a conversation.