Shops I worked when on Tandem:
Equity & Law in England.
Data Architects.
Logica (they merged/bought Data Architects).
I worked on large back-office funds transfer solution
called "BESS" (Bank Electronic Support System).
This basically acts as a big "hub" for a bank's electronic
connections to the Federal Reserve, S.W.I.F.T, CHIPS, Telex and so on.
They had other products too but most of them stemmed either directly
or indirectly from BESS.
I wrote mostly software running in Tandem's Pathway environment
(requesters, servers, TMF, Enscribe, Guardian C30).
Because of the complexity of our product, we were popular with Tandem
as beta sites for their new 0Ses. I found a nasty bug in the first D-series
release (remember the low-pin/high pin release?). That's my claim to fame. God I need a life :-)
I left Tandem platforms in 1994 to code C++ on NT.
I'm now writing web apps on Weblogic using J2EE (EJBs, servlets, jsps).
I still miss Tandem even today.
What about you? Which shops?