Principal C# Developer .Net AWS - FinTech

Client Server; Greater London; Hybrid; GBP 100,000 - 120,000; Full time

Benefits offered by this job

Salary up to £120k

Bonus (20%)

Pension (5% employer contribution)

25 days holiday (27 after 2 years / 30

Life Assurance (4x base salary)

Employee Assistance Programme

Training and development

Cutting-edge technology

Job summary

Client Server is seeking a Principal C# Developer in London with hybrid WFH to lead architecture and delivery of scalable fintech solutions on the .NET stack. You will champion modern practices, mentor teams, and work closely with the CTO to shape technical strategy.

The role involves building high-quality backend systems, applying AI capabilities, and delivering features in a fast-paced Agile environment with two-week sprints and clear stakeholder collaboration.

Qualifications

• Strong knowledge of modern C# backend development and SOLID design.
• Experience with Python coding and AWS.
• Experience on highly scalable systems.
• Solid CS fundamentals: OOP, data structures, design patterns.
• Interest in AI and exploring tools like ChatGPT, Claude, Copilot.
• Excellent analysis, problem solving, organisation and planning.
• Strong communication and stakeholder management.

Responsibilities

• Architect and build high-performing, scalable solutions in the Microsoft stack.
• Adhere to SOLID principles and best practices in development.
• Collaborate with cross-functional Agile teams in 2-week Sprints.
• Lead adoption of AI initiatives (e.g., chatbots) and explore AI possibilities.
• Work with the CTO and provide measurable outcomes.

Skills

C#

Python

AWS

OOP

Data structures

Design patterns

AI interest

Problem solving

Communication

Stakeholder management

Job description

Principal C# Developer / Engineer (C# .Net AWS Python) London / WFH to £120k

Would you like to join a growing and profitable scale-up that is viewed as a leading FinTech disruptor in a senior role that will allow you a great deal of influence and progression?

As a Principal C# Developer 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.

Location / WFH:

There's a hybrid policy, with two days in the brand new London offices and flexibility to work from home two days a week (Thursdays and Fridays).

About you:

• 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 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

What's in it for you:

• Salary to £120k
• Bonus (c20%)
• Pension (5% employer contribution)
• 25 days holiday (increasing to 27 after two years and 30 after)
• Life Assurance (4x base salary)
• Employee Assistance Programme
• Range of training, career development and supported learning
• Impactful role working on cutting edge technology