Users upload a spreadsheet or JSON data file and display that information on a map of the United States. There is support for filtering, toggling, numeric and categorical mapping as well as many other visual configuration options like color schemes.
This empowers users to display a lot of different kinds of data easily.
Users needed an intuitive and robust way to quickly build their maps. I designed and built an editor interface that enables them to quickly make the changes they need and instantly see the results on the map.
Even though CDC.gov is a traditional website and not a single page application, React was the best tool to handle managing all the different changes to the DOM quickly and efficiently. The map embeds on CDC.gov pages (and other websites if sharing is enabled) through an iframe.
This allows all of the code for the maps to be self contained without worry of affecting other elements on the site.
The CDC values open source software and it was considered imperative that I build this mapping software on open source foundations. After completing the project, I was able to release a version of this software as open source for other people to use.
Although CDC Maps is used by many locations in the CDC, it was notably used in 2020 to display U.S. cases of COVID-19 and was viewed by tens of millions of users every day.
I also rapidly developed and deployed additional features just to support this very critical map.
The tool that this replaced had been in use for over 5 years, was very buggy and difficult for users to navigate. Some centers preferred to use outside vendors to do this kind of visualization instead of the built in tool.
Now centers are very happy to use this tool and there is a long roadmap of planned additional features to make this a mature, featureful piece of software that is used across the CDC and eventually the federal government and beyond.