Category Theory: its concepts and applications

https://www.cl.cam.ac.uk/teaching/1819/L108/

Less abstract:

http://chalkdustmagazine.com/features/an-invitation-to-category-theory/

https://raw.githubusercontent.com/jwbuurlage/category-theory-programmers/master/doc/categories_for_programmers.pdf

https://unglueit-files.s3.amazonaws.com/ebf/e90890f0a6ea420c9825657d6f3a851d.pdf

Types reasoning:

http://www.lambdadays.org/static/upload/media/1456307974627874bartoszlambdadays2016.pdf

Category Theory Applied to Functional Programming

http://www1.eafit.edu.co/asr/pubs/others/cain-screen.pdf

https://media.readthedocs.org/pdf/pycategories/latest/pycategories.pdf

https://teki-con.com/wp-content/uploads/2018/04/anat-category_theory_teki_con.pdf   

Categories for the working Hackers:

https://homepages.inf.ed.ac.uk/wadler/papers/categories/qcon-sf.pdf 

https://cukic.co/files/presentations/2014-12--monads-in-chains--ivan-cukic--meeting-cpp.pdf 

http://yowconference.com.au/slides/yowlambdajam2018/Hopkins-AllOfBasicCategories.pdf 

http://www.worldcolleges.info/sites/default/files/C%2B%2B_In_Action.pdf 

http://gpu.wigner.mta.hu/user/pages/03.events/02.lectures-on-modern-scientific-programming/04.lectures-on-modern-scientific-programming-2015/Session6_DeepMagic2.pdf