Python Developer

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

Job summary

A leading technology recruitment company is seeking a Senior Python Developer based in London. The role demands an expert in Python with strong DevOps and data processing capabilities. Key responsibilities include designing high-performance financial software and mentoring junior engineers. Candidates should have over seven years of experience in software development, especially within Financial Services or Energy Trading. This position promises exciting challenges in a dynamic environment.

Qualifications

• 7+ years in professional software development, particularly in Financial Services or Energy Trading.
• Exceptional communication skills to convey technical concepts to non-technical stakeholders.

Responsibilities

• Design and build robust, low-latency Python solutions.
• Lead system design and transition legacy scripts to microservices.
• Engage directly with Traders, Quants, and Product Managers.
• Conduct code reviews and promote continuous learning.
• Troubleshoot production issues in a high-pressure environment.

Skills

Expert Python (3.9+)

Advanced use of pandas

Strong advocate for TDD/BDD

Expert Git

Deep knowledge of PostgreSQL

Education

BSc/MSc in Computer Science

Mathematics or related Engineering field

Tools

Docker

CI/CD pipelines

Kubernetes

Job description

Overview

We are seeking a high-calibre Senior Python Developer to join our London-based Engineering squad. Sitting at the heart of our Front-Office analytics platform, you will bridge the gap between complex energy market fundamentals and high-performance software engineering.

You will be responsible for the architecture and delivery of scalable data products that power real-time trading decisions. As a senior member of the London hub, you will act as a technical lighthouse mentoring junior talent, driving TDD standards, and ensuring our cloud-native infrastructure is as agile as the markets we trade in.

Responsibilities

• Engineering Excellence: Design and build robust, low-latency Python solutions for processing large-scale financial and energy market datasets.
• Architectural Leadership: Lead decisions on system design, transitioning legacy scripts into scalable, containerised microservices.
• Stakeholder Engagement: Partner directly with Traders, Quants, and Product Managers to translate market requirements into production-ready code.
• Mentorship: Conduct rigorous code reviews and foster a culture of continuous learning for our mid-level and junior engineers.
• DevOps Culture: Own your code from local dev to production, leveraging CI/CD automation and Kubernetes orchestration.
• Operational Integrity: Troubleshoot business-critical production issues in a high-pressure, time-sensitive trading environment.

Technical Requirements

Core Stack (Must Have)

• Expert Python (3.9+): Mastery of OOP, Design Patterns (Factory, Strategy, Observer), and logical data modelling. Familiarity with recent PEPs.
• Data Science Tooling: Advanced use of pandas and SQLAlchemy. Experience with parquet and Arrow for high-performance memory management.
• Testing: Strong advocate for TDD/BDD (Pytest, Behave); experience in building automated integration test suites.
• Modern DevOps: Expert Git, Docker, and CI/CD pipelines (Azure DevOps/GitHub Actions).
• SQL Mastery: Deep knowledge of PostgreSQL or SQL Server (Query tuning, indexing strategies, and complex joins).

Preferred Skills

• Cloud & Orchestration: Hands-on Kubernetes (AKS/EKS) including Helm charts and StatefulSets.
• Market Knowledge: Previous experience with ETRM systems, tick data, or financial risk analytics.
• Build Tools: Experience with Poetry or uv for modern dependency management.

Qualifications & Experience

• Experience: 7+ years in professional software development, with a significant tenure in London’s Financial Services or Energy Trading sectors.
• Education: BSc/MSc in Computer Science, Mathematics, or a related Engineering field.
• Soft Skills: Exceptional communication skills; the ability to explain complex technical trade-offs to non-technical stakeholders in a fast-paced environment.