The months spend on building these, are often spent on becoming domain expert of one or several sub domains, build into the artifact. Which is not visible to the outside world. Its similar to hiring one or several consultants, but the consultants were that one person, digging into fluid dynamics and what not to write that one system. The problem is often not in the software, but in the "domain" self-schooling one has to go through, to understand the process happening. Like sending a person to university again, but on the clock with a deadline.

https://en.wikipedia.org/wiki/Fast_inverse_square_root

Best example of an alien artifact i could come up with on the fly: The using parties do not understand it, but can reuse it. They will have a hard time modifying it. To understand the properties, a deep understanding of math is needed, and how the inverse square root can be mapped to the binary properties of a float.