Atheists in 1999 might have to go Usenet comp.lang.scheme to find Scheme experts.
(Scheme polo shirt at church in 1999? My first guess is around Rice University. Second guess is Indiana.)
And of course MIT. https://archivesspace.mit.edu/repositories/2/archival_object...
I was at MIT in 1999, and class T-shirts occasionally happened, and there were tens of churches within walking distance, for historic reasons, but not a lot of churchgoing people from the universities themselves, that I'm aware of.
But who knows: toplevel works in strange and mysterious ways.
> My work place was using it in production, 1999. A ton of code was written by a VERY SMART (and famous) person and of course it worked. He delivered it under pressure, ahead of schedule and it just worked. Ok, but my frustration was that we could not find anyone to support the decoders.
Actually, except for the "famous" part, that sounds a bit like a major system in Scheme for which I was hired by a very smart person who'd done 10x or 100x development on it. And it just worked, and we could evolve it rapidly, and keep it just working. In 1999, it probably would have been based in New Jersey.