Senior Software Engineer

Location: London office

Department: Engineering

We’re looking for a Senior Software Engineer to help us accomplish our mission to improve and extend lives by learning from the experience of every person with cancer. Are you ready to be the next changemaker in cancer care?

Flatiron Health is a healthtech company using data for good to power smarter care for every person with cancer, around the world. Flatiron partners with cancer centers in the US, Europe and Asia to transform patients’ real-life experiences into real-world evidence and create a more modern, connected oncology ecosystem. Our multidisciplinary teams include oncologists, data scientists, software engineers, epidemiologists, product experts and more. Flatiron Health is an independent affiliate of the Roche Group.

We’re looking for an experienced software engineer to join the Healthcare Data Products team. Our mission is to build scalable pipelines and platforms that transform raw clinical data into actionable insights, and to empower our clients to do the same. Whether it’s managing a 100+ source data lake or architecting Snowflake-native sharing solutions, your work directly impacts how cancer data is utilized across the industry.

What You’ll Do

As a Senior Engineer on the HC Data Products team, you will own the lifecycle of high-scale data applications. From our Snowflake data lake to customer-facing data retrieval interfaces, you will build systems that are robust, compliant, and performant. In addition, you’ll:

• Architect & Scale: Design and maintain complex data pipelines using Python, PySpark, Prefect, and Airflow to ingest data from hundreds of sources into Snowflake.
• Innovate Infrastructure: Transition our data delivery models toward modern Snowflake-native data sharing and high-performance Parquet extractions.
• Full-Stack Ownership: Support our EHR application and data export features by working across the stack, from Python backends to React frontends.
• Modernize Tooling: Use Terraform (via Spacelift), Docker, and GitLab CI/CD to ensure our infrastructure is code-driven, while leveraging Datadog and Metaplane for end-to-end system and data observability.
• High-Velocity Dev-Ex: Leverage cutting-edge AI-assisted development tools like Cursor and Claude Code to streamline workflows and focus on solving complex oncology data challenges.
• Collaborate: Partner with oncologists, product leaders, and data scientists to translate complex product and regulatory requirements into elegant technical solutions.

Who You Are

You're a kind, collaborative, and passionate problem-solver who thrives at the intersection of software engineering and data platform architecture.

• The Experience: You have 4+ years of professional experience building scalable, production-grade software.
• The Stack: You are highly proficient in Python and have a deep understanding of relational databases (Snowflake preferred).
• The Mindset: You have a nose for value and empathy for your internal and external customers. You proactively identify problems that have a high impact on the business. 
• The Communicator: You can explain complex data flows to non-technical stakeholders and mentor junior engineers on best practices.
• The Academic: You hold a degree in Computer Science or a related field (or have equivalent foundational experience).

Extra Credit

• Modern Data Stack: Experience with Airflow, Prefect, PySpark, or Terraform.
• Front-End Flair: Experience with React or similar JS frameworks for building data-heavy internal tools.
• Cloud Native: Hands-on experience with AWS services (S3, EMR, EC2).
• Healthcare Context: Familiarity with healthcare data domains (e.g., Clinical, Financial, or Research) and an understanding of provider workflows within an EHR.
• Open Source: You contribute to the community or have a passion for building developer tools.

Who We Are

Our people are at the centre of everything we do. We strive to foster a culture where our teammates feel equipped and empowered to make meaningful contributions with confidence, compassion, and clarity.