I gave a talk about FreeBSD on Firecracker at bsdcan a few years ago. Sorry I'm on my phone just before an orchestra concert so I can't give you a link but if you Google "BSDCan Colin Percival Firecracker" you should find it on YouTube.
I watched that video when it was published, and really enjoyed it, as well as most of the BSDCan presentations. I subscribed to the YouTube channel, but there any other similar conventions that you would recommend? I've found that the Chaos Communication Congress presentations are hit and miss, but BSDCan presentations are quite regularly succinct and entertaining.