Ask HN: What are the best books with problem sets that test your understanding?

Some especially good ones

Sipser -- Theory of computation

Pinter -- Abstract algebra

Kleppner and Kolenkow -- Mechanics

Klein -- Organic Chemistry as a Second Language

There are several principles for reference: 1. Exercise quality: Exercises must cover core concepts, have a reasonable difficulty level, and preferably come with answers or explanations. 2. Practice orientation: Deepen theoretical understanding and cultivate application capabilities by solving problems. 3. Classics and reputation: Give priority to books that have been recognized by the academic community or learners for a long time.

Solve real life problems from work. It's easy to solve problems, so practice being a problem spotter.

It has been a while since I worked through it, but Haskell programming from first principles had some pretty good exercises IIRC.

You could do worse than The Art of Computer Programming.