I was in this exact position a month ago and I landed a great job because of doing very well in two technical interviews. I also am a strong Python programmer who was rusty on the classic CS stuff. Go to Codility's programming lessons page:

https://app.codility.com/programmers/lessons/1-iterations/

and try to do at least two exercises from each lesson up to lesson 15 if you can. The open reading material at the top of each section is excellent and discusses all the CS theory you will need.

Good luck!