Thanks, could you provide some material recommendations?
I'll share one: I've really, really enjoyed 'Graph Theory' by Bondy and Murty (2007 edition): https://www.springer.com/kr/book/9781846289699. Disclaimer: it's much more focused on the mathematical / combinatorial aspects of graphs than on concrete algorithms, although there are some algorithms in there. Some math background recommended.
but right now I'm starting with basics on S. Gill Williamson Foundations of Combinatorics with Application.
I don't mind pure reasoning, but I need practical programming uses to at some point. (maybe joblessness anxiety showing)
I also have some graph books but since it relies on combinatorics rapidly ..
I don't know much in the way of more advanced expository combinatorics books, other than the more narrow Generatingfunctionology (Wilf) and the already mentioned Enumerative Combinatorics (Stanley).