Last May I had the chance to go to London to speak about developing HTML5 games with Phaser. The conference was WebProgressions, and it was a nice experience!
Some talks I recommend you to watch are Ruth John's Web Audio and Web MIDI (she shows some cool demos!), Progressive WebApps at The Guardian[^1] by Alex Sanders, and also Sole's Moving to HTTPS with Let's Encrypt.
So here's the video of my talk. I'm sorry there is a some background noise, specially at the beginning. The slides are here, as well as the online demos showing off what is covered in the talk.
[^1]: Pro tip: Whenever you see a front-end talk delivered by an engineer working for a British newspaper, go watch it.