In a recent ESA job posting on a jobs mailing list (curiously far more detailed than the online version), I saw the line:

This Research Fellow Opportunity aims at testing of breadboard retrieval algorithms.

What is a breadboard (retrieval) algorithm? Google Search yields precious few results, mostly from ESA:

Albert, Preusker, and Fischer (2012), ENVISAT workshop:

Originally, three breadboard algorithms were developed

Wikipedia tells me that, in electronics, a breadboard is a construction base for prototyping electronics. The details of the article do not appear relevant for the algorithm usage, but it makes me guess that the meaning of breadboard is related to prototyping.

What does breadboard mean in the context of Earth observation retrieval algorithm development (which are the only contexts I could find)? Is it simply a synonym for prototype, or does it have a different meaning?