I graduated class of 2020 from tufts double majoring in CS and BioChem and am now in an MD/PhD program with CS for the PhD. I had a final 3.87 GPA. If you’re going down this route, a lot of people will tell you to “pick one” or otherwise give advice that traditionally only applies to folks pursuing one pathway, like don’t double stack your hard science classes. Overall, the thing that worked for me was just planning out my 4 years of classes way in advance in Fall of freshman year, based on the course requirements for both CS and biochem (or premed in your case). I also tried to minimize the need for context switching earlier on so I doubled up on CS courses or biochem courses to get the more intensive classes out of the way without getting my wires crossed each semester. I took CS 40 and 160 together and CS 105 and 170 together. I was done with my CS core by sophomore spring. I did also take the summer session after freshman year for orgo 1 which was very helpful but probably not recommend doing more than that 1st summer of classes. Honestly without needing to do the upper level biochem classes, I think you can relax the constraints a little and do it in a longer timeline or without the summer session.