Looks like he's posted slides here: https://twitter.com/noelwelsh/status/730449315789934593

I also really liked his talk on probabilistic programming: https://www.youtube.com/watch?v=e1Ykk_CqKTY

The talk was recorded. I don't know when it will be online. The talk doesn't go heavily into details (no talk of coalgebras) but spends time trying to explore what good code means in the FP and OO paradigms.