I was at a conference in Northern Virginia some months ago and saw a presentation from the folks at Upside, a startup specializing in booking business travel. They described the legacy system which handles pretty much all booking in the US, a system called SABRE. They described it as an ancient 6-bit computer system in Texas with no modern API. Everything they do tech-wise is a modern wrapper around that system. So I…
Not sure where "6 bit" is coming from though, and you can use gcc/c++ now, not just assembler[2]. And it's in Tulsa, Oklahoma, not Texas. Sabre's HDQ is in Texas, the data center is not. The hardware is very modern and new Z series mainframes in big loosely coupled clusters.
Amadeus, Sabre's main competition, also still has TPF at the core.
There is one notable non TPF reservation system. http://www.navitaire.com/ Last I checked, it couldn't scale well enough to handle a large airline.
Both Sabre and Amadeus are replacing TPF, but one function at a time (shopping, fare engine, booking, check in, etc). And very slowly.
[1]https://en.m.wikipedia.org/wiki/Transaction_Processing_Facil...
[2]https://www.ibm.com/support/knowledgecenter/en/SSB23S_1.1.0....
Fwiw, TPF is basically a huge, distributed, and transactionally consistent nosql database. Most orgs still using it have extracted most of the business logic that was in it, out to Linux boxes that front it. Not for stability reasons, but faster time to market with new features. To date, attempts to replace the high contention and high transaction rate nosql type traffic haven't scaled well enough.
Just in the US, 2.5 million people fly each day. And the processes to sell, board, etc each passenger are lots of transactions each. It's a pretty big scale. I think it's fairly close to Amazon sales per day, but with more contention and sub transactions.
All Visa credit card transactions are also still on TPF.