Depends on what you are looking for and your background. From Harvard in particular: https://cs51.io https://book.cs51.io/ https://cs61.seas.harvard.edu/site/2023/

Some random ideas: https://mitp-content-server.mit.edu/books/content/sectbyfn/b... https://sourceacademy.org/sicpjs/index https://www.nand2tetris.org/ https://www.youtube.com/playlist?list=PLyqSpQzTE6M_dZdF7Bd-U... https://algs4.cs.princeton.edu/home/ https://haskell.mooc.fi/ https://www.youtube.com/playlist?list=PLF1Z-APd9zK5uFc8FKr_d... https://openlearninglibrary.mit.edu/courses/course-v1:MITx+6... https://pages.cs.wisc.edu/~remzi/OSTEP/ https://craftinginterpreters.com/ https://www.youtube.com/@6.824 https://exercism.org/tracks