Hello, ifle, you wrote: I Recommend to begin with Java Tutorial, the basics trail, the first some heads. I> 1. On what write? There is free Eclipse, idea yet a variant, there was a support in VS Code. Intellij IDEA Community Edition to you to begin with quite suffices, it is a free product. If not a variant not because of the price (?) Then it is unconditional Eclipse. VS Code it is frivolous. I> 2. As I understand for API it is necessary/is possible to use Spring. Yes, it makes sense. Spring Boot 2.0 just quitted, look at once it. If speech about API for potentially slow algorithms, look at once on Webflux and do asynchronous implementation. I> 3. Maven it as msbuild and nuget. msbuild it is the conditional equivalent Apache Ant, the tool of generation before last, nuget probably it is possible to consider as analog Apache Ivy (or small part Maven). Maven it is other paradigm of control of your code (the standard ). If to create the new project from zero you have a choice between Maven (XML, the big spanning on ) and Gradle (DSL, "easier" form of the description of the project). I> 4. Not so clearly how to add the existing project in new, basically there some libraries connected among themselves. Collect your code in library, connect it as dependence in Maven. All. I> While I am confused and something is not so clear that such classpath, like idle time Set of ways in and names of files of libraries from which JVM will load compiled code. In Java Tutorial you teach to write it manually but so now nobody does - it is possible to collect so-called "fat jar" in which all dependences are included, or to generate an application launch script under a specific platform. I> 5. For structural we use Serilog, what in Java the popular? SLF4J as API, Logback or Log4J 2.0 as implementation (if not to use specific a feature, it is possible to replace one at any moment with another, without forgetting to correct configs).