Looking for novels that the MC is/was a Scientist.. And then using his/her knowledge in another world (reincarnated/summoned) Something like Parallel World Pharmacy / Release that Witch
Warlock of magus world, but instead of previous world knowledge is more of the previous world methodology to research magic
The Super High Schoolers Affording to Live in Another World! (Read the manga. If I'm not mistaken, one of the MC's a medical genius of sort) Knights & Magic (MC's a programmer & mecha otaku. He uses his programming skills when scripting magics, essentially enhanced it & his model kit knowledge when building mecha (essentially, Gundam Build Fighters in fantasy medieval magic world w/ 1:1 working scale models LOLS)) Mahouka Koukou no Rettousei (MC's basically Steve Jobs of magic tools development)