the main distinction i like to make is:
your FDEs shape your product strategy, and should be considered R&D. after making sure a customer deployment is successful (by any means necessary btw, even if it means building new systems outside of the product), the crucial next step is to drive the product improvement with PMs and core software engineers after contact with reality. this was a pretty radical idea from palantir in the era of saas
if you only do step 1 you're basically just solutions engineers / mckinsey, and if you only do step 2 with no customer learning to your product you don't improve your platform for all the other customers. the pain becomes the moat
There's a reason why this echelon of companies comp FDEs much, much more than services businesses is because you're trying to find engineering + product + customer facing in one (knew people making 200k+ 5 years ago as new grad FDEs, and the same flavour at the labs is 500k+ easy)
that being said the role has evolved a lot over the years, and depending on the company it could be indistinguishable from solutions eng, or sales eng, or even dev rel.
I put something similar another comment. What you describe is a tough job that requires dedication and the ability to objectively differentiate yourself through your work across multiple disciplines. I’ll copy it here: “The real question is how do they actually reward the people who excel in this role, and do they really recognize who’s delivering or do they look at gamey metrics and pedigree” I worked at a technical consultant out of college and it was a lot of the first category but often my small team did step 2. Yet it was never promoted by the larger corporate hierarchy because the incentives were not there. I would love to a job like this because I’m so nerdy but also charismatic and have perspective. Knowing myself and how dedicated I would be, I wouldn’t take anything less than 250kz