Experienced data engineer with a background in statistics and mathematics.


  • October 2021 to Present: Data Engineer, Sainsbury's (London, UK)
    • Maintain and develop large ELT pipelines for structured and semi-structured data from many data sources including providing out-of-hours support. (AWS S3, Airflow, Snowflake)
    • Designed and built a robust application to automate managing AWS database migration service tasks. (Python, boto3)
    • Identified and fixed devops issues across teams and implemented solutions to prevent future issues through CI and improving team culture. (GitHub Actions, Circle CI)
  • July 2019 to October 2021: Strategic Consultant (Data Engineering), Amey Strategic Consulting (London, UK)
    • Lead data engineer of a GIS (Geographic Information System) dashboard creating insights into operations and tracking KPIs for a local county council. (AWS, Kubernetes, Airflow)
      • Created ETL pipelines to load data from IoT devices, online APIs and daily reports into a central database. (Python, Airflow, Postgres)
      • Maintained the production platform by monitoring alerts, quickly fixing bugs and pre-emptively hardening code by implementing CI checks. (Azure Pipelines)
      • Identified an inefficiency in the client's work allocation and developed a predictive machine learning model to enable data-driven planning. (FB Prophet)
    • Collaborated with the HR department to analyse the gender pay gap of thousands of employees across all departments in the company.
      • The visualisations, statistics and forecasts I produced guided the company when becoming a living-wage employer.
    • Completed a focused two-week analytics sprint evaluating the output of a contract with a local council.
      • Collected user-stories and datasets from the client's team to understand their processes and goals.
      • Delivered an engaging presentation with insightful data visualisations highlighting key successes and opportunities for improvement.
  • June 2018 to September 2018: Data Science Services Intern, Asia Analytics Taiwan (Taipei, Taiwan)
    • Created extensions for data cleansing and data mining in SPSS and SPSS Modeller using Python and R.


  • 2015 to 2019: MMath Mathematics, 2:1 (University of Exeter, UK)
    • Dissertation used regression and Gaussian processes to provide human-understandable insights into to machine learning algorithms. Successfully modelled a neural network using multiple techniques in a way that simplified the complex internal system to well-understood statistical processes. (R, Keras)


  • September 2020: Microsoft Certified: Azure Data Scientist Associate
  • May 2020: Microsoft Certified: Azure Fundamentals


  • As well as being fluent in Python, SQL and Typescript, I develop open-source projects in Julia and Rust as a hobby. My portfolio of personal projects can be found on my website (ha.nnes.dev).
  • Languages: English (native), Afrikaans (fluent), Spanish (intermediate) and Mandarin (beginner).