Most common Machine Learning/ Natural Language Processing projects developed for/in businesses

I currently work as a data scientist developing software that classifies PDF documents into certain categories, using Machine Learning models with Natural Language Processing methods. I am thinking about finding a certain niche or specialization to work in either full time or as a freelancer.

I have some idea where Machine Learning (and Natural Language Processing) are being used in in actual businesses, for example Chatbots, Product Recommendation, etc., however i would like to know:

1. What kind of Machine Learning and/or Natural Language Processing projects/implementations are most commonly implemented?

2. What kind of roles/tasks in such ML/NLP projects are most sought after, most needed?

Any help is appreciated.