https://leetcode.com/
(my account : https://leetcode.com/sokazaki/ )
I referred to many people's solutions, to name a few, @caikehe, @jianchao-li, @kitt, @lee215, and more.
Thanks so much for their sofisticated codes and ideas.
[Time/Space Complexity, Coding Style]
https://wiki.python.org/moin/TimeComplexity
http://bigocheatsheet.com/
https://pep8.org/
[Software Engineering/Machine Learning News]
https://softwareengineeringdaily.com/
https://lexfridman.com/ai/
[Algorithm and Data Structure]
https://github.com/yangshun/tech-interview-handbook/tree/master/algorithms
https://www.toptal.com/developers/sorting-algorithms
https://algorithm-visualizer.org/
https://qiita.com/drken (※ Japanese)
https://yukicoder.me/wiki/slide (※ Japanese)
[System Design]
https://github.com/donnemartin/system-design-primer/
https://www.educative.io/collection/5668639101419520/5649050225344512
https://www.school.ctc-g.co.jp/columns/nakai2/ (※ Japanese)
https://www.oreilly.com/library/view/designing-data-intensive-applications/9781491903063/ (※ Book)