Extremely limited transferable skills outside of doing Appian work. They will dispute this but my options when I looked to get out were either lateral moves to companies wanting to do Appian implementation, or entry level jobs elsewhere.
They made money off my constant overtime, which I was repeatedly told was not typical, but not even a mention of that extra work graced my annual reviews.
On that note, no bonuses.
I felt misled about the technical aspect of the role. Interviewed for "consultant" role but was referred to as a "developer" on the day to day.
Career growth heavily tied to the success of the project you're on, which as an Associate Consultant you do not realistically have control over as long as you're not dragging your feet on development.
Increased work with "partner" companies means it's not uncommon to be the only Appian employee in your team. I knew of a number of people in that circumstance.
Make a show of asking for your preferences for projects but never once was a preference of mine taken into account.
Opaque and vague feedback structure
Appian's long term goal is to take "low code" and make it "no code". with respect to the first point, you can see how this leads to concern.
If you're trying to avoid feeling like a proverbial cog in the machine by staying away from more traditional tech consulting firms, I'd advise to stay away from Appian Professional Services as well.
I really considered not posting this in case it could be determined who I am, but ultimately decided that a review like this could have positively impacted my life, and I'd want to be able to do the same for someone reading these now.