Occasional, mostly engineering and/or recreational mathematics content. A few highlights:
https://news.ycombinator.com/item?id=16790338 : The Mathematics of 2048: Optimal Play with Markov Decision Processes
https://news.ycombinator.com/item?id=12385707 : How a Technical Co-founder Spends their Time: Minute-by-minute Data for a Year
https://news.ycombinator.com/item?id=21209216 : Lessons from Building Node Apps in Docker