County assessor’s code repository powers transparent government

A move toward open source and away from legacy technology has helped the Cook County, Illinois, Assessor’s Office (CCAO) become more transparent, enabling residents to better understand their property assessments.

To create a transparent digital platform, CCAO began in 2018 to replace many paper-based and siloed records used to help assessors predict the value of real estate. “There were scripts for modeling and for other purposes that were sitting on people’s personal computers or on Windows shared drives and nobody really knew what ran what, which version was running what model. It was quite a mess,” said Daniel Snow, a data analyst at CCAO. 

The team started to sort things out by looking for a version-control system. They landed on GitLab because they liked its take on open source and “wanted to support people who were interested in supporting open source,” Snow added. Since then, the team has added more features, including continuous integration and continuous discovery (CI/CD). 

Now, all the scripts that run CCAO’s real estate value assessment models, handle reporting and ingest certain datasets to serve the models are in GitLab. Other processes are still on other systems, mainly because they don’t have code associated with them or the code is not public, Snow said.

“The big, most useful change that we’ve made has been moving a lot of our integration and testing to CI/CD because GitLab’s pipelines are very handy, including testing for the model,” Snow said. “We actually run the model on GitLab’s runners, so whenever you make a code change to the model, it will do an additional run and basically test to make sure that nothing is broken.”

CCAO officers use GitLab’s Git history, issue tracker and milestones, documenting every project in real-time. Additionally, the office moved internal documentation that was also on a shared drive to GitLab’s built-in group wiki. 

The real estate value assessment modeling work began in 2019, when CCAO was preparing to reassess one-third of the county’s 1.8 million properties – a yearly process that’s used to levy taxes and determine property tax distribution in the country’s largest assessment jurisdiction of its kind. 

Since the county moved to the more transparent digital platform that allows property owners to view and understand how assessments are established, more than 6,700 people have download the datasets. 

“It’s been very interesting to find one or two users here and there who are actually looking at our repositories and reviewing things and will make comments,” said CCAO Chief Data Officer Samantha Simpson. “It’s pretty cool to get some feedback from a person that we didn’t know before and to really get a sense of who’s looking at our data, where they’re from, what understanding they have of what we’re putting out. I think one of our goals is to continue to nurture that.”

Internal transparency has improved, too, Scott Smith, the office’s chief communications officer added.

“This allowed us all to work more collaboratively, which was really helpful,” especially in 2020, Smith said. “COVID-19 had a real impact on our ability to work within an office, and … we would not have been able to [work remotely] had we not moved on to these new systems and onto Git. That was really not something any of us were anticipating, but what we did anticipate was the need for folks to be able to work more collaboratively together wherever they were.”

“I think what Cook County is experiencing is what a lot of our other customers experience as well, which is providing visibility,” GitLab Public Sector Area Vice President Bob Stevens said. 

A benefit of the platform is enabling people who are not coders to make comments and recommendations that developers can use to improve products, he added. That supports code production or changes quickly, hastening speed to mission.

Additionally, it “shifts security left,” Stevens said. “Rather than waiting until the end of the development cycle to run scanners to determine if you’ve got vulnerabilities in the code, you can actually do it as you submit a line of code so you don’t end up at the end with this huge list of vulnerabilities that you’ve got to go now address.”

“The ability for us to every year be able to continue to make improvements to our model and work in an iterative way, I think has been really helpful,” Smith said. “In addition to putting all of our repositories up for the public, for those who are versed in computer science or maybe our data journalists who want to use that, we’ve also been putting information up on the Cook County data portal. The team just refreshed all of that work, which allows you to see 20 years of assessment data. So this is not just about us being transparent about the work our administration is doing the past four years. It’s allowed us to really create a path toward transparency of the work of the last several administrations.” 

Simpson said this work aligns with CCAO’s overall modernization objectives. For instance, the office is looking to replace the 1970s era mainframe that still runs the county property tax system. 

“At every level of government there has been an initiative to define what open government looks like, what open source looks like,” she said. “That helps save money for taxpayers. It saves money on resources when you know that other agencies have data that you can usually pull and use to help better serve the public. We are … just taking it in stride with where we are technically in our office and what we can produce and what makes sense for us to be able to do as a continuous practice.”

Stephanie Kanowitz is a freelance writer based in northern Virginia.