This article is part of the “Meta Advent 2019” series. I’ve committed to writing a new blog post here every day until Christmas. nREPL has many interesting aspects of its design and its notion of sessions is definitely one of those. In this article I’ll try to shed some light on sessions and explain their usefulness. Note: If some of the terminology in this article (e.g. nREPL messages) is unclear to you, please consult nREPL’s design documentation for a quick overview of the key concepts. Simpl...