I agree that vending machines are really a mess. However I recommend the Deutsche Bahn Navigator App. If you have an account you can easily get most tickets.
Also states like Baden-Württemberg got their act together recently and made it possible to book tickets all way through.
I recently was in Netherlands trying to get from the Hague to the islands south of Rotterdam and it was also quite confusing.
I was just in Amsterdam. One of our locals there said that, although there's an ongoing switch to just tapping contactless credit cards, he advised just getting a contactless transit chip card because even if it cost a few dollar more it would more reliably work everywhere. Things have improved in most places over time but it can still be confusing for the occasional visitor.
I remember at some point pre-pandemic I was in the UK with a friend and we had all these these different tickets/receipts were trying to use to go through a turnstile and doubtless really pissing off the people lined up behind us but it was super-unintuitive what we needed to stick into the machine.
> I recently was in Netherlands trying to get from the Hague to the islands south of Rotterdam and it was also quite confusing.
You can just swipe your phone (Apple Pay / Google Wallet) or credit/debit card to check in and out (do not forget to check out!) and you're done. Works for all public transport in the Netherlands.
Of course there are also more traditional ways to pay for your ticket, but it does not get much simpler than this imo.
Their codebase has to be a wild ride. There are still traces from the days it ran as Windows binaries in CGI fashion (very much doubt they still do it like that, just like a large number of eBay URLs still contain the ebayISAPI.dll bit from the time the site was literally a Microsoft IIS plugin). On the DB instance it also outputs like five different generations of UIs depending on the exact parameters you hand it. You can also find several different iterations of APIs, like one search API will output actual, non-trivial JS code to fill auto-completes, another gives you JSON with a totally different format and yet another XML with everything slightly different again. From their job postings it follows their backend is C++.
The previous system came from the 80s and ran on multiple Tandem/Nonstop clusters.
As far as I am aware, although the system is very capable it started as someone's PhD thesis in the mid 80s and has been developed since then.
I worked on the data prepartion for a small HAFAS installation at one point and the specification was an absolute mess of fixed with text, delimited text and XML, sometimes all in the same file!
In my experience the TVMs in Berlin were fine, but it was easier to just get the app because I don't make a habit of carrying around a ton of cash. The biggest problem I had was the TVMs at the Frankfurt airport, half of which were broken, and none had a clear explanation of what the different ticket types were.
Also states like Baden-Württemberg got their act together recently and made it possible to book tickets all way through.
I recently was in Netherlands trying to get from the Hague to the islands south of Rotterdam and it was also quite confusing.
but the new ticket is really nice wrt booking.