Senior Software Developer (Python) Company: Fathom Location: Bristol (Hybrid working available) Type: Permanent Salary: Competitive About Fathom Fathom is a leading flood modelling company that provides cutting-edge risk assessment solutions to help organizations understand and manage flood risk across the globe. Our advanced models support insurance companies, governments, and businesses in making informed decisions about flood-related risks. Role Summary We are looking for an experienced Senior Software Developer with a strong background in Python and data analysis tools, especially within a scientific setting, to join our team and contribute to our Global Catastrophe Model. This is an excellent opportunity to work with state-of-the-art natural catastrophe risk models running via OasisLMF, working with large-scale geospatial datasets to deliver robust and accurate risk assessments. There will also be opportunities to contribute to other projects, such as our customer facing API which is primarily written in Golang. The successful candidate will combine strong Python programming skills with an understanding of scientific computing, contributing to the continuous improvement of our modelling capabilities while working as part of a collaborative and innovative team. They will live and breathe software development best practices, delivering well-tested and documented code. Key Responsibilities Software Development Write clean, maintainable, well-documented and fully tested Python code Collaborate with team members on code reviews and best practices Contribute to the development of internal tools and utilities Participate in testing and validation of model implementations Model Development & Maintenance Maintain and enhance existing natural catastrophe risk models within OasisLMF Implement model improvements and optimizations to enhance performance and accuracy Debug and resolve technical issues in model implementations Ensure model outputs meet quality standards and validation requirements Data Processing & Management Process large geospatial datasets including GeoTIFFs and Parquet files Develop efficient data pipelines for model input preparation Implement automated data quality checks and validation procedures Team Collaboration Work closely with other members of the catastrophe modelling and technical teams Participate in technical discussions and planning sessions Share knowledge and contribute to team learning initiatives Support other team members when required with programming support and code reviews Essential Requirements Education University degree in Computer Science, Mathematics, Physics, Engineering, or related quantitative discipline Technical Skills Expert skills in data manipulation using Python and tools like Pandas and NumPy Experience with writing and maintaining comprehensive test suites (unit, integration, end-to-end) Familiarity with CI/CD pipelines (e.g., GitHub Actions) Experience with containerization (i.e. Docker) Experience working with large datasets, particularly: GeoTIFF files and raster data processing Parquet files and columnar data formats Version control systems (Git) Professional Experience At least 5 years of relevant professional programming experience Experience working in a collaborative development environment Demonstrated ability to work with complex scientific or technical datasets Personal Attributes Strong analytical and problem-solving skills Attention to detail and commitment to code quality Excellent communication skills for team collaboration Ability to work independently while contributing to team objectives Desirable Requirements Technical Skills Experience with other geospatial libraries (GeoPandas, Rasterio, Shapely, Fiona) Experience with newer Python tools such as Polars and DuckDB Cloud computing platforms such as GCP and AWS Experience with spatial databases (PostGIS) Experience building and maintaining production APIs Experience with other languages such as Golang and build tools like Bazel Professional Experience Experience working with environmental or climate data Research experience in relevant scientific fields What We Offer Competitive salary commensurate with experience Hybrid working arrangements with flexibility to work remotely Opportunity to work with cutting-edge flood risk modelling technology Professional development opportunities and training Collaborative and innovative working environment Chance to contribute to meaningful work addressing global flood risk challenges Application Process To apply, please submit: Current CV highlighting relevant experience Cover letter explaining your interest in the role and relevant experience We are committed to equal opportunities and welcome applications from all qualified candidates regardless of background.