Honest question: I'd really love to know what UTF-8 traps people fall into all the time when working on a consumer product with Java - especially given that Java basically stores all Strings in UTF-16 (well, starting with Java9+ there's some "optimizations" made, but still). I literally can count those issues on one hand in over a decade of working on such (multilingual) products.
I also completely fail to see what a CRUD app (i.e. java + db) + shooting REST requests to confluence has to do with your concurrency questions, as in interview != job fit, but that might have to do with some missing context.
Based on your review and the other replies in this thread I bought the book - I hate to say this, but, in my honest opinion, it was mostly a dull, arrogant and self-aggrandizing book. (Side-Note: I lost my mother at a somewhat young age to cancer and am no complete stranger to death and the process of dying).
Because I find debating about the pro's and con's about microservices somewhat cumbersome, I tried to let the code speak and record a screencast series on exactly this topics. (https://www.marcobehler.com/series/9-microservices-the-good-... ) Because I feel that especially in the Java world, Microservices are an utter abomination most of the time. Comments more than welcome!