I've worked quite a bit doing migrations and integrations against one of their products. The database schema is... interesting. This thing obviously started as a Sweden-only product, so the database schema for the Swedish version has Swedish column names (first mistake here). When they wanted to build a version for the larger Nordic market they decided to translate the column names to English (well, ok...). But since they already had a lot of customer installations using the Swedish version they have maintained 2 parallell database versions, essentially identical - except for all column names - for something like 20 years now. For this product they have also maintained a home grown version of Visual Basic for automation tasks within the system. Essentially VB6 except lots of bugs and quirks that are so old that if they fix them now, literally millions of man-hours will be required to migrate the existing automations that rely on those quirks.