Richard Ellingson

Senior software engineer with experience in data engineering

Senior Software Engineer at ArrowDot (2026-02 – Present)

• Established engineering best practices (testing, code review, documentation, etc.) across a large, high-complexity monorepo, measurably improving development velocity and reducing regression rates.
• Identified and resolved critical architectural flaws in ArrowDot's AI app builder, eliminating critical vulnerabilities and bugs, and improving platform reliability.
• Designed and shipped a backfill system to apply newly developed optimisations to existing AI-generated applications, ensuring consistency across the platform.

Senior Software Engineer 2 at Zappi Store (Intellection) (2023-12 – 2026-01)

• Designed and built the ELT/ETL pipeline replacing Zappi's legacy storage and data modelling platform, processing 100 million records across hundreds of clients.
• Reduced large, complex client data export times from 5+ days to under 3 minutes — approximately 10,000x faster than the previous pipeline.

Senior Engineering Manager at Zappi Store (Intellection) (2021-12 – 2023-12)

• Managed the data modelling team, overseeing engineers across Cape Town and London.
• Led technical hiring across Cape Town and London offices, conducting 200+ engineering interviews from 2016–2023.

Software Engineer → Senior Software Engineer at Zappi Store (Intellection) (2015-02 – 2021-12)

Data engineering and modelling for market research companies including YouGov, TNS, and Millward Brown, primarily in Ruby (Rails), Elixir (Phoenix), Python (Pandas, NumPy) and React.

• Designed and maintained Quattro, a domain-specific language functioning as a Ruby-to-scientific-Python interpreter for market research data analysis.
• Built AST optimisers for Quattro, including predicate push-down and rule-based subtree substitution, reducing average query times.
• Engineered a fault-tolerant extension framework for Quattro, enabling distributed teams to safely add language functionality without breaking core behaviour.
• Designed, built and maintained Zappi's data resolution, sanitisation, caching, and advanced filtering pipeline, serving concurrent analysts across hundreds of client accounts.
• Designed and built both the backend and parts of the frontend of the most widely used stats application across Zappi's analysis platform.

Associate Software Developer at ACI Worldwide (2014-08 – 2015-01)

Developed and maintained online payments software, primarily in Java.

Software Developer at S4 Integration (2013-07 – 2014-07)

Developed software for an international engineering and manufacturing company, primarily in C#.

BSc Comp Sci Honours in Computer Science – Nelson Mandela Metropolitan University (2013-01 – 2014-10)

BSc Comp Sci & Applied Mathematics in Computer Science & Applied Mathematics – Nelson Mandela Metropolitan University (2009-01 – 2012-11)