Python Developer

About Phi Partners

Phi Partners is a global Capital Markets IT consultancy specialising in Front Office and Risk Technologies for Tier-1 investment banks, hedge funds, and asset managers. Founded in 2004 and headquartered in London, we operate across North America, EMEA, and APAC, delivering deep technical expertise. Our consultants work directly with trading desks, quantitative teams, and technology stakeholders to deliver projects that are both technically complex and commercially critical.

We are continuing to expand our London presence and Centres of Excellence across Europe and the Americas, with senior engineers leading strategic buildouts focused on low latency eTrading, market connectivity, and modern data platforms. Our programmes often involve enhancing legacy trading and market data systems, improving data integration pipelines, strengthening performance and resilience, and supporting the introduction of new asset classes and functionalities. This environment offers engineers the opportunity to work on high-impact, front-office-aligned initiatives while contributing to modernisation efforts across the broader technology stack.

About the Programme

Our client is a North American Tier-1 investment bank with whom we have maintained a long-standing professional relationship, having supplied over 80 consultants. They are currently undertaking a major transformation of their interest rate trading technology stack, focusing on modernising pricing, risk, and trade booking systems while moving from legacy infrastructure to a Python-based microservices architecture.

The team sits in Pre-Trade Analytics and builds and maintains distributed platforms that price high volumes of trades and produce intraday risk metrics, operating at scale with a focus on performance, parallel processing, and reliability. This role involves working on core trading infrastructure, contributing to platform modernisation, performance improvement, and the development of scalable analytics systems used by global markets teams.

Roles and Responsibilities

You will work closely with global technology teams, quantitative analysts, and front-office stakeholders to deliver high-performance Python systems.

Key responsibilities include

• Designing and building scalable Python services for pricing, risk, and trade analytics
• Supporting the migration of legacy platforms to modern microservices architectures
• Developing distributed systems that process large volumes of trades in parallel
• Improving system performance, including latency, throughput, and resource utilisation
• Investigating and resolving production issues, including pricing discrepancies and system defects
• Writing clean, maintainable, and well-tested code aligned with enterprise standards
• Contributing across the full software development lifecycle, from design through to production support

Key Skills

Necessary

• Strong Python engineering experience in production environments
• Experience building large-scale distributed systems or microservices architectures
• Experience with numerical or analytical libraries such as NumPy or SciPy
• Experience with modern tooling such as Kubernetes, Docker, or similar frameworks
• Ability to work in complex enterprise environments with changing requirements
• Deep hands on experience in testing across all levels
• Strong problem-solving skills with ownership of end-to-end delivery

Nice to have

• Experience in capital markets or trading environments
• Good understanding of performance optimisation, concurrency, and parallel processing
• Understanding of financial instruments, especially interest rate products
• Exposure to distributed computing or large-scale data processing
• Experience working on platform modernisation or migration programmes Additional traits:
• Experience building scalable enterprise platforms using Python and distributed architectures
• Quantitative development experience, including derivatives, pricing, or financial analytics