Dataport is kinda hit and miss when it comes to developing. It was created by taking the small IT departments of different ministries, agencies, etc, of multiple states, and putting them all under a common roof. They did that because they realised that standard state administration structures and IT weren’t really compatible but on the flipside, they also funded a whole new organisation with people accustomed to those very structures, and as dataport is still a public law corporation the internal administration – think payroll and everything – will still be done by career state bureaucrats.

It’s a different kind of dysfunction than you see in the private sector but dysfunction nonetheless. OTOH working directly with FLOSS upstream will help: It’s not that (sufficiently large) FLOSS projects don’t have their own bureaucracy, and the bureaucrats that be on dataport’s side will respect that.

Regarding maintenance: Aside from hardware upgrades because they make sense (power consumption) or you want new features (latest addition: Graphics tablets to allow citizens to sign stuff without having to print things), there’s a constant churn in software requirements as new orders come in on what to do and how to do it. Just because you wrote perfect software doesn’t mean that parliament stops passing laws.

As far as usability is concerned: Dataport will also have to train people, and they actually have the funds to do usability studies and such. Much will also depend on the different agencies they’re working for, can’t fix an agency’s workflows for them, and that goes beyond mere IT. I guess a public-law consultancy does make sense but having a ministry for administrative affairs reeks of Sir Humphrey. I guess you could hide it by making it a subsidiary of the court of auditors.