" I'd like to warn you though, that because I'm more or less familiar with the subject, I think it will be very difficult to find what I'm asking for."
Cool. Rather than posted challenges, how about educating us to why we are wrong. If you know this area well I'd be interested to learn more.
Programming languages, compiler design and construction, operating systems, networking on all levels including protocol design, traffic analysis, etc; multithreading, games, browsers, document management systems, financial applications, telephony, CAD's, a lot of web development - are among the areas I worked in during my career. (I never touched signal processing though.)
Although in some narrow areas I've seen non-trivial calculus, but I barely remember anything that involves infinities and is significant for the solution.
You're still not answering my questions. Do you believe that no engineers use limits or calculus? Do you believe that limits and calculus are unrelated to the idea of infinity?
Now you seem to be saying: "I have never, myself, seen the concept of infinity used to solve a problem in a way I deem significant. Therefore, infinity does not exist and is not useful to anybody."
If I said the same thing about the number 65536, would it force you to program only 8-bit processors for the rest of your life?
Based on some of your earlier statements, I'm going to guess that we're using different definitions of the word "infinity." I'd guess that to you, the word "infinity" means something like "the largest possible number, denoted ∞." I'd also guess that, in your claim about calculus above, you mean something like "I have never seen a calculus problem whose solution required you to write down an ∞." Am I right?
Cool. Rather than posted challenges, how about educating us to why we are wrong. If you know this area well I'd be interested to learn more.