As I wrote in a previous article, one of the distinctive features of IoT projects is that they require integration of technical blocks originating from three different domains: electronics, communications and software. And inside these three domains, various different subdomains are usually involved: analog and digital electronics, wireless communication modules, protocol stacks, embedded software, user interfaces, database management, analytics, geospatial data, etc.
Therefore, when developing a new system, it's almost impossible to only rely on technical blocks developed in-house, or that you have been already using for a long period: you have to integrate some new components provided externally. And usually you'll discover that provided documentation does not say everything about components characteristics and behaviour.
Today, with my youngest son, we were able to test in real conditions the 
I have to spend some time on a project that will provide and use REST APIs. After a rapid comparison between Play and Spring (see below), I start with Play and Scala. I'm a beginner in Play and in Scala, so assume that information below can be naive or incorrect.
In the beginning of the 2000s, while I was still working for the small company I had cofounded, we decided to answer a Request for Proposal submitted by a waste removal company, for a system allowing to check whether all planned daily garbage collections had been performed. At this time, we didn't know a lot about the waste removal market. But we knew we were experienced enough in technologies we would have to assemble in order to answer the RFP: onboard equipment and embedded software, GNSS positioning, wireless communications, Geographical Information Systems, etc.
