I think part of the problem is that TSB had extremely limited access to the existing system, which affected their understanding of how that existing system worked, the kinds of testing they could do, and their ability to do incremental migrations.
That might've been the case, but it can't be the excuse.
They were spending €100mil a year on maintaining the current infrastructure. The team's incentive is to save a large portion of that through the migration, and somebody higher up should've given them unlimited access to do so.
They were paying €100mil a year to a direct competitor who owned and operated the current infrastructure for them. The amount of money they were paying was, if anything, a direct incentive not to give them the access required for the migration.
> They were spending €100mil a year on maintaining the current infrastructure.
As I understood they were made to pay that as the infrastructure was being used of another bank
