From my experience with the game, I believe their progression margin is quite large. For example, they don't cache anything client side (even Pokestop assets),

From my experience with the game, I believe their progression margin is quite large. For example, they don't cache anything client side (even Pokestop assets), nor do they timeout/retry/prefetch after a network disconnect during a Pokemon capture (which is very annoying on spotty 3G networks). Last but not least, battery consumption is insane. Don't go out without a spare battery! Backend side, I also noticed a few cases of "blinking pokemon" in the nearby grid. Surely symptomatic of synchronisations issues between instances of distributed systems (dirty reads?). I enjoy the game a lot, but regarding the number of issues, it's still a beta.