Senior Software Developer

Harnham; Greater London; On-site; GBP 110,000 - 160,000; Full time

Job summary

Harnham in London seeks a Senior Software Developer to join a high-performing engineering team. You will build and optimise C#/.NET applications across greenfield and data-intensive projects, taking ownership of design decisions and delivering scalable solutions.

The role involves mentoring peers, contributing to architecture, and collaborating with stakeholders to shape product direction. This is an in-office role five days a week in London.

Qualifications

• Strong commercial experience with C# and .NET.
• Experience building backend systems and full stack applications.
• Solid understanding of software engineering fundamentals, architecture and design principles.
• Experience with relational databases such as SQL Server.
• Clear communication of technical concepts.
• Proactive, self-driven learner.
• Interest in sports and understanding of major sports structures.

Responsibilities

• Designing, building, and optimising high-performance C#/.NET applications.
• Leading the delivery of greenfield projects and enhancements to existing platforms.
• Contributing to system architecture, design decisions, and performance optimization.
• Developing scalable solutions that process and manage large volumes of data.
• Collaborating with highly skilled engineers in a cross-functional environment.
• Taking ownership of projects and contributing ideas throughout the development lifecycle.
• Mentor and support other developers while promoting engineering best practices.

Skills

C#/.NET

Backend systems

Full stack

Architecture & design

SQL Server

Communication

Learning mindset

Sports knowledge

Job description

London (5 days a week in office - no flex)

This is an opportunity for a Senior C# Full Stack Engineer to join a high-performing engineering team working on complex, data-intensive systems. You will have significant ownership over technical decisions, contribute to the design of scalable software solutions, and play a key role in delivering projects that have a direct impact on the business.

THE COMPANY

They are a technology-led investment business that leverages advanced analytics, automation, and software engineering to drive decision-making. With a collaborative and highly technical culture, they have grown steadily while maintaining a strong focus on quality, innovation, and employee retention. Engineers are given the autonomy to influence projects, contribute ideas, and work closely with stakeholders across the business.

THE ROLE

As a Senior Software Developer, you will build and enhance high-performance C#/.NET applications, working across greenfield projects, real-time data systems, and complex engineering challenges.

Specifically, you can expect to be involved in the following:

• Designing, building, and optimising high-performance C#/.NET applications
• Leading the delivery of greenfield projects and enhancements to existing platforms
• Contributing to system architecture, design decisions, and performance optimization
• Developing scalable solutions that process and manage large volumes of data
• Collaborating with highly skilled engineers in a cross-functional environment
• Taking ownership of projects and contributing to ideas throughout the development lifecycle
• Mentor and support other developers while promoting engineering best practices

SKILLS AND EXPERIENCE

The successful Full-Stack Software Developer will have the following skills and experience:

• Strong commercial experience with C# and .NET
• Experience building backend systems and full stack applications
• A strong understanding of software engineering fundamentals, architecture, and design principles
• Experience working with relational databases such as SQL Server or similar
• The ability to communicate technical concepts clearly and effectively
• A proactive approach to learning and professional development
• An interest in sports and a general understanding of how major sports are played and structured

BENEFITS

The successful Full-Stack Software Developer will receive the following benefits:

• Salary between £110,000 - £160,000 - depending on experience