Principal Python Developer.

Principal Python Developer - London (1-2 days onsite, hybrid) - Inside IR35 rate negotiable

We are seeking multiple Principal Python Developers to join a major programme building a new data platform in AWS. These roles require strong expertise in Python development within financial services in financial market data.

You will play a senior, hands-on role in designing and developing scalable data solutions, working with Spark, AWS, and Aurora PostgreSQL to deliver a high-performance, cloud-native data platform.

Key Responsibilities

• Design, build, and optimise data-driven solutions using Python in a financial markets environment
• Develop and maintain distributed data pipelines using Spark and AWS-native services
• Work with Aurora PostgreSQL and other AWS data services for storage, querying, and analytics
• Integrate and process financial market data feeds (transactions, market/FX data, asset management systems)
• Contribute to the design and delivery of a new AWS-based data platform, ensuring scalability and performance
• Collaborate with data engineers, architects, and product teams to align technical delivery with business needs
• Apply best practices in testing, CI/CD, and Agile delivery methodologies

Skills & Experience Required

• Proven experience as a Python Developer with a focus on data platform development
• Strong expertise in financial markets data (transaction feeds, private banking, asset management, trading platforms, FX)
• Hands-on experience with Apache Spark for distributed data processing
• Proficiency with Aurora PostgreSQL
• Strong working knowledge of AWS cloud services, especially for data engineering and platform builds
• Experience delivering in complex, data-intensive environments
• Excellent problem-solving skills, with ability to operate as a senior/principal engineer in Agile teams