Serif font used throughout the presentation.
Clavo by Michał Jarociński.
PT Mono by Alexandra Korolkova with participation of Isabella Chaeva.
I think you meant PT Serif. Still, I'm not sure that's it: note the lowercase “r” in the word “Grid” in the first two pics and the top serif on the uppercase “A” in the last one.
Yes, you're right, I posted it influenced by your other post since this one also had a monospace part, sorry.
And no, I'm afraid it's not PT Serif either.