Semantic Search: Theory And Implementation

It took me a long time to realise that search is the biggest problem in NLP. Just look at Google, Amazon and Bing. These are multi-billion dollar businesses possible only due to their powerful search engines. My initial thoughts on search were centered around unsupervised ML, but I participated in Microsoft Hackathon 2018 for Bing and came to know the various ways a search engine can be made with deep learning. Do you find this in-depth technical education about NLP applications to be useful?