its a hot potato alright and as someone who worked on a project related to millenium IT i can say that sometimes i dont get their logic. definitely not straightforward.
so i see 3 parties to blame here
2. the vendors
3. millenium it
i know the mentality of a stock exchange. they definitely do no not want to be in the wrong and scare investors away. having said that there is no humanly possible way (to my knowledge) of testing that replicates real live production use. during mock sessions you will find some vendors and or brokers would say they "already tested" and do not need the mock session thus removing several necessary variables from the testing (and also giving a pass on the updated api). and the data packets could be dropped any where along the route. (if something is wrong and you cant trace it - blame it on the firewall!) did anybody check if the backbone can support all the data that now comes with the increased speed?
the vendors would probably underestimate the level of complexity involved in programming a brand new api. which comes up to a very useful and important question: did ANYBODY at the vendor read the api before they even began the programming? and i already mentioned the updated api testing issue. and when i say vendors i also lump the exchange's own data vendor in the pot which by virtue of their relationship should actually have a leg up but human psychology being what it is
millenium it - in an effort to speed up their performance they use their own in house proprietary db before or after the data hits the oracle servers. what the.. ? oh and the db software is called nORA for "NOT oracle."
and finally, a project this big - heh - give me a million dollars if you can find somebody who understands the entire infrastructure, IT or business side of the project! why coz its not just one project, they probably rolled out their in house surveillance software at the same time.
i wont even talk about level of involvement of the government regulators
phew - years of pent up frustration coming out. but i pity the little guys there. yes they worked so hard and diligently and they did their part but because someone in some other team decided to take the easy route out
ps. dont bother with nda infringements as i am in no way related to the lse or millenium it or any of those vendors