Vendor lineage
Serpro - the federal government's data processing
Runs the systems a Brazilian citizen cannot opt out of.
Serpro is the Brazilian federal government's data processing service, and it operates the category of system that has no competitor and no acceptable downtime: tax collection, foreign trade, federal registries. When a system like that is unavailable, the alternative is not a different supplier - it is that the function of government stops for the day.
That constraint produces a different engineering culture from the commercial estates most of this timeline documents. Change is slow because a failed change has no commercial consequence and a constitutional one; systems live for decades because replacing them requires the country to keep operating during the replacement; and the platform choices of the 1970s and 1980s are still present because nothing forced them out.
It also sits at the centre of Brazil's national computing story. The market-reserve period was justified partly by the argument that a country should not depend on foreign suppliers for exactly these systems, and Serpro is what that argument was built around.