As mentioned in my original comment with additional: I wrote an application that ran on Raspberry PI devices in different continents, countries, and time zones that connected to trackers worn by people with zero technical skills and worked nonetheless surviving disconnection events and automatically upgrading the software, communicating with the trackers and sending serialized data (protobufs) to a server application in Scala my colleague wrote, that then made analysis and aggregations and sent result to yet another mobile application (Android) another colleague wrote to display graphs and other data. The application I wrote worked with several models of this company's products, and at some point, we thought of making it more generic and use it for video and sound feeds for another project ("sound event detection", let's say).

Yes, I was able to build a custom app and it worked not only on my data, but on others' data as well.

The funniest conversations we had were about time and time zones. At some point, we started using timestamp timestamp and timestamp not timestamp because working on data from multiple time zones makes you question what on earth is time, and what actually is now ("Now for whom?" "Now where?").

I had literally nightmares about time and time zones. No, I am not kidding.