European software regulation does not arrive as an event. It arrives as a sequence of dates, each attached to a different instrument, each with its own scope test, and most of them written for a reader who is not an engineer. The result is that the question teams ask — are we compliant? — has no answer, while the question they should ask has four.
This guide takes the four instruments a European software product is most likely to sit under and reads each one for its engineering consequence: who it binds, when, and what it asks a delivery team to actually do differently. It is written from the practitioner side. We are a software consultancy in Warsaw, not a law firm, and where an answer genuinely depends on legal advice we say so instead of guessing.
The useful question is never "are we compliant". It is "which of these binds this entity, by when, and what does it change about how we build".
One structural point before the chapters. Three of the four instruments below have a size or sector test, and a great deal of published summary skips it entirely, which is why so many teams believe obligations apply to them that do not, and miss ones that do. Scope first, obligations second.