As I (and my now partner Eevee) race towards the level 8 finish line, I don't feel quite the same. I see us making limited progress and see the number of people finishing level 7 rising, haha. This is fun, though.
I've worked in/with security along these lines for a very long time. This CTF (particularly level 8) has been some of the most difficult stuff I've ever done. Thanks to Stripe for putting this together; if I wasn't already a customer, I absolutely would be now!