Recently I had a chance to explore SharePoint modern list formatting using JSON. I must say it is fun and powerful feature to build highly customized UI right from out of the box list without using custom code solution.
If you are looking to customize list column or row UI then here are very useful Samples available which will give you a good place to start.
For more detail about syntax of JSON and what is involved in term of accessing data as well how can you override existing UI, visit Use view formatting to customize SharePoint
Here is final output of the profile card