A tarn (or corrie loch) is a mountain lake, pond or pool, formed in a cirque excavated by a glacier. A moraine may form a natural dam below a tarn.
https://github.com/davepinch/pinchy.cc/blob/master/content/topics/geology/landforms/tarn/en.wikipedia.org.md
[David O.] Sacks is a member of the so-called “PayPal Mafia”, a group of founders and early employees of PayPal who went on to found a series of other successful technology companies. They are often credited with inspiring Web 2.0 and the re-emergence of consumer-focused Internet companies after the dot com bust of 2001.