Senior C# Developer - Head of Core Platforms | Hedge Fund | London

Undisclosed; City Of London; On-site; GBP 80,000 - 120,000; Full time

Job summary

A leading investment management firm in London is seeking a Head of Core Platform to lead the transformation of their core technology. This pivotal role requires hands-on development in C# and .NET and expertise in fixed-income trading systems. You will design and implement a contemporary core stack, liaising closely with senior stakeholders. The position offers a chance to shape high-performance systems in a collaborative setting that values technical excellence and innovative ideas.

Qualifications

• Strong background in fixed-income trading systems is essential.
• Hands-on development experience in C# and .NET is required.
• Experience in front-office trading technology environments.

Responsibilities

• Lead the transformation of the core technology stack.
• Develop and consolidate systems, guiding a team of developers.
• Oversee the implementation of a real-time portfolio valuation system.

Skills

Fixed-income trading systems

C# and .NET

Python

OOP backgrounds (C++, Java, Go)

UI technologies (WinForms, WPF, Blazor)

Job description

The Client

Our client is a highly regarded discretionary investment manager with a strong focus on data‑driven decision making. They operate with a small, agile structure and are recognised for their commitment to excellence in trading and technology.

Their in‑house technology function spans IT infrastructure, software development, and quantitative analysis, supporting all aspects of market data processing and trading activity. The environment is fast‑paced, collaborative, and highly technical, where code quality, performance, and low‑latency systems are top priorities. Engineers work across domains, contribute to architectural discussions, and help shape scalable, robust systems.

We have partnered with this team for several years and have a close, direct working relationship with the CTO. We have successfully placed multiple individuals into the group and can provide detailed insight into the team structure, culture, and expectations.

The Role

The client is embarking on a major initiative to unify and expand their core systems, bringing more of this capability in‑house. As Head of Core Platform, you will lead this transformation—designing, planning, and implementing the evolution of the core technology stack to create a strong foundation for future growth.

This is a hands‑on leadership role. You will develop and consolidate systems, write software, guide a team of developers, and take ownership of several critical platforms. This includes an in‑house C# PnL and Risk system that performs real‑time portfolio valuation, alongside other components that will be integrated into a cohesive, modernised core platform.

You will work closely with senior stakeholders including the CTO, COO, Head of Operations, and Project Management.

Candidate Profile

Domain Expertise

• Strong background in fixed‑income trading systems
• Knowledge across front‑, middle‑, and back‑office workflows
• Demonstrable expertise in :
• Repo trading and lifecycle management
• Post‑trade operations, clearance, and settlement
• Margin and collateral management
• Experience building systems that capture bond and swap (interest rate and FX) cashflow events
• Understanding of accrual (trade date) and realised (settlement date) accounting reconciliations
• Particular interest in candidates with Fixed Income and Rates experience

Technical Skills

• Strong computer science fundamentals
• Hands‑on development experience in :
• C# and .NET (essential for this role)
• Python within quant or data environments
• The client will also consider exceptional engineers from other OOP backgrounds such as C++ , Java , or Go
• Familiarity with UI technologies such as WinForms, WPF, Blazor Hybrid, and Blazor Web

Leadership & Approach

• Experience working in front‑office or trading‑technology environments, or on business‑critical systems
• Ability to lead by doing—hands‑on while guiding a team
• Pragmatic, delivery‑focused mindset
• Commitment to high‑quality engineering practices and low‑latency, high‑performance systems
• Low‑ego, high‑performing self‑starter who values ownership, teamwork, and delivering commercial, pragmatic solutions

Why Apply

This is a rare opportunity to take ownership of a mission‑critical transformation within a high‑performing investment manager. You’ll shape the architecture, engineering standards, and long‑term technical direction of the firm, working in a collegiate environment where ideas matter and technical excellence is valued.

As a long‑standing recruitment partner to this team, we can provide deep insight into the role, expectations, and culture, ensuring you have a clear and accurate understanding of the opportunity.