I'm interested again in finding a search engine tutorial to follow to get me aquainted with the finer points of building a search engine based on an open source search solution.

ElasticSearch is popular and I found this tutorial, only a couple years old:

In this multi-part series, we will explore how to build a search engine. It will be quite powerful and industrial strength. The first part will focus on getting the right tools and getting technology stack ready. We will build this search engine with an AngularJS front-end and use elasticsearch as the computation back end. (How to build a search engine: Part 1 - Machine Learning Blogs. (n.d.). Retrieved from machinelearningblogs.com/2016/12/12/how-to -build-a-search-engine-part-1/)

I like Solr but I hear good things about ElasticSearch so this tutorial might be a good one to follow for me. Maybe for you as well.