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# Principal Software Engineer

- **Company:** Client Server
- **Location:** London, UK (Remote available)
- **Salary:** £110,000.0 - £130,000.0
- **Contract:** Permanent contract
- **Skills:** Artificial Intelligence, Amazon Web Services, C Sharp (Programming Language), Data Structures, Software Design Patterns, Python (Programming Language), Object-Oriented Software Development, Backend
- **Published:** November 6, 2026
- **Apply:** https://www.client-server.com//job/principal-software-engineer-c-net-aws-fintech-5/apply

## About the Role

* You are an experienced Software Developer / Engineer with a strong knowledge of modern best practice
 * You have strong C# backend development skills, ideally also Python coding skills
 * You have a good knowledge of AWS
 * You have experience of working on highly scalable systems
 * You have technical project leadership experience
 * You have experience in a FinTech or start-up environment
 * You have a strong knowledge of Computer Science fundamentals such as OOP, Data Structures, Design Patterns
 * You have experience with, or a strong interest in Artificial Intelligence and are keen to explore the possibilities further e.g. ChatGPT, Claude, Cursor, Copilot
 * You have strong analysis and problem solving skills alongside organisation and planning abilities
 * You have business acumen and advanced communication / stakeholder management skills

## Description

As a Principal Software Engineer you will architect and build highly performant and scalable solutions using the Microsoft tech stack and SOLID design principles, collaborating with cross functional Agile project teams in 2 week Sprints, you'll be an advocate of best practice and ensure software is delivered to schedule.

There's a host of new features and development work and you'll also help to drive the adoption of AI within the business, introducing things like chat bots and exploring the use of AI to make process improvements.

This is an impactful role where you'll report into and collaborate with the CTO, you'll have a lot of visibility and quickly see the results of your work.