Do you have a favorite set of lectures on the Finite Element Method? Possibly a set of lectures with a heavy list of programming exercises that encourages students to build all the building blocks of a modern software library?
This set of lectures from Prof. Clayton Pettit, although it is not development of libraries oriented, mostly cover the fundamentals and solving algorithms and it is pretty complete IMHO.
Lectures by Bangerth, if you don’t mind C++.
https://www.math.colostate.edu/~bangerth/videos.html
A good book and a very “practical” approach with examples and applications to natural sciences. Matlab codes for all chapters incl. exercises, by Guy Simpson: Practical Finite Element Modeling in Earth Science Using Matlab
Bangerth’s lectures with deal.II for implementation are a fantastic resource!
Another one that I particularly like (though slightly leaning on the math side) is https://finite-element.github.io/ which basically teaches building things from ground up and is similar in spirit to the high level interface offered by FEniCS/Firedrake etc. I think this approach is baked in the lectures because Dr. David Ham who teaches the implementation part is one of the lead authors of Firedrake.