[StabbyCutyou]

Thanks! In terms of backend engineering, I'd say one of the trickiest things is always depending deeply on a third party service or provider to be the backbone of the value you add.

That's a pretty high level answer, but in general that's the most difficult to wrangle with over time, in my opinion.

To give a more concrete answer, every slack instance and the way people configure it can be a little different, and in some cases we found it tricky to find the right consistent location to pull information like display names from.

In terms of what is unexpectedly easy, Slack themselves been great at giving us feedback and advice for building on their platform!