Loved the podcast and reminded me of a book I read in college: The Cross-Time Engineer. From Amazon’s description:
THE RIGHT MAN FOR THE JOB
One moment Conrad Schwartz was a hungover hiker in the mountains of modern Poland, the next he was running for his life from an angry Teutonic knight.
At first Conrad just thought he’d stumbled across a mad hermit. But several days of ever stranger events convinced him that he had somehow been stranded in A.D 1231.
And that meant Conrad had to turn Medieval Poland into the most powerful country in the world. Otherwise the Mongols were destined to destroy it–in just ten years!
I read 4 of the 5 books (my roommate at the time had them) and it was very interesting and cool, and I happened to be an engineering student at the time too. I remember that there was a rule that they could not affect things in the past, but could possibly do small things if there was a relative involved, and it turned out that someone in the time-machine company was related to Conrad - so they couldn’t bring him home, but did leave some better armor and stuff for him to “find.”
I might have to re-read them and find the 5th book.