Case Study: Cook County’s Assessor’s Office achieves transparent, version-controlled property assessments with GitLab

How Chicago’s Cook County assesses economic data with transparency and version control

Cook County’s Assessor’s office, which sets values for about 1.8 million properties (roughly $270 billion in estimated market value), faced fragmented, paper-based records and legacy scripts with no version control or documentation. To increase transparency, reproducibility, and agility in its valuation processes, the Assessor’s office adopted GitLab to publish code, manage datasets, and create a public, single source of truth.

Using GitLab’s repositories, issue tracker, Git history and milestones, the office moved to public, version-controlled workflows that document changes, errors, and fixes in real time. The effort produced more than 1,400 commits across public repositories (with thousands of dataset downloads), enabled data-driven COVID-19 valuation adjustments, improved forecasting and accountability, and delivered measurable government transformation through GitLab’s transparent code and version-control platform.

Cook County’s Assessor’s office

Robert Ross

Chief Data Officer