The video doesn't quite show what is the great features that Hotknot delivers while NFC couldn't. To me, it comes down to the choice between literally touch vs proximity. I prefer the latter that NFC delivers.
On the other hands, BLE is aiming the eWallet market as well. It might be interesting to compare all 3 techologies and rate their pros and cons.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.