Principal Software Engineer (Hybrid)

Fastmarkets; Greater London; On-site; GBP 70,000 - 90,000; Full time

Job summary

A global commodities information provider in Greater London is seeking a principal engineer to lead the development team. In this role, you will design scalable systems, deliver high-quality code, and mentor junior developers. The ideal candidate has extensive experience with C# and .NET, a strong understanding of distributed systems, and a passion for clean code. Join us in shaping the future of market data technology.

Qualifications

• Experience with C# / .NET Framework.
• Solid understanding of concurrent programming.
• Proficiency in Test-Driven Development.
• Experience building distributed systems.
• Strong communication skills.

Responsibilities

• Guide coding best practices within the team.
• Deliver high-quality, performant code.
• Provide mentorship for junior engineers.
• Contribute to technical direction.

Skills

C# / .NET Framework

Concurrent programming

Service Bus or Event Hubs

Test‑Driven Development

Building distributed systems

RESTful APIs

ASP.NET / Web development

SQL and NoSQL databases

Strong communication skills

Mentoring junior developers

Tools

.NET 8.0 or higher

Azure cloud services

Distributed caching technologies (Redis)

Job description

About Fastmarkets

Fastmarkets is an industry‑leading price‑reporting agency (PRA) and information provider for global commodities, offering price data, news, analytics and events for agriculture, forest products, metals and mining, and new‑generation energy markets. With a history dating back to 1865, Fastmarkets supplies critical data to customers seeking to understand and predict dynamic markets, enabling more effective trading and risk management. The company operates worldwide, employing over 600 people across the UK, US, China, India, Singapore, Brazil, Belgium, Finland and beyond.

Job Overview

Our next‑generation real‑time market data platform operates 24×7 globally, connecting to over six financial exchanges and delivering market data, benchmark prices, news content and research to customers worldwide. This role is an exciting opportunity to shape and build the platform that will underpin the next phase of Fastmarkets’ digital growth.

Role Summary

As a senior member of the development team reporting to an Engineering Manager, you will serve as a principal engineer. You will contribute to the strategic and technical direction of the Technology Team while being a highly productive developer passionate about clean, high‑quality code. Your responsibilities will include designing fault‑tolerant microservices, building scalable web and mobile UIs, and fostering an engineering culture that prioritises metrics over opinion. You will mentor junior developers and provide technical leadership as an individual contributor.

Key Responsibilities

• Guide coding best practice within the team
• Deliver high‑quality, performant code that adheres to SOLID design principles
• Provide mentorship and guidance for more junior engineers
• Contribute to the overall strategic technical direction of the platform

Key Interfaces

• Engineering Manager
• Software engineering team
• SRE
• Enterprise Architect
• Product Owners / Product Management

Required Qualifications

• Experience with C# / .NET Framework
• Solid understanding of concurrent programming
• Familiarity with messaging technologies such as Service Bus or Event Hubs
• Proficiency in Test‑Driven Development and Continuous Integration
• Experience building distributed systems, RESTful APIs, and SOA
• Skills in ASP.NET / Web development
• Experience with SQL and NoSQL databases
• Strong communication skills and a collaborative attitude
• Proven ability to develop real‑time, low‑latency systems
• Experience mentoring and growing junior developers

Preferred Qualifications

• Experience with .NET 8.0 or higher
• Knowledge of Azure cloud services
• Exposure to FIX or SBE message processing or similar
• Experience with garbage‑free .NET development
• Familiarity with distributed caching technologies such as Redis
• Skills in stress testing, performance tuning, and code benchmarking
• Background in C++ (current or previous experience)
• Experience designing and deploying microservices
• Understanding of networking protocols (UDP, TCP)
• Experience with Continuous Delivery pipelines
• Knowledge of market data, commodity exchanges, and financial instruments

Personal Attributes

• Deeply technical and detail‑oriented
• Committed to continuous improvement for yourself, team, and processes
• Strategic thinker capable of executing in a fast‑paced environment
• Highly collaborative and comfortable working across teams and geographies
• Results‑driven with a focus on long‑term value creation

Our Values

• METRICS DRIVEN – we use insights to improve customer experience and business performance
• ACCOUNTABLE – we keep our promises and get things done
• GROWTH MINDSET – we adapt quickly to changing realities with urgency
• INCLUSIVE – we celebrate diversity and ensure everyone feels they belong
• CUSTOMER CENTRIC – we put customers at the heart of everything we do
• COLLABORATIVE – we work across teams and capitalize on diversity