My brother once suggested that there are probably bits of code/algorithms that would be world changing if they were released in academic journals, but instead were written by some unknowing programmer in an afternoon for their job coding embedded systems for refrigerators.

This particular example may be unlikely, but it's a very fun idea.

An anonymous 4chan user once solved a 25 year old maths problem, to answer a question about the watch order of an anime. https://www.scientificamerican.com/article/the-surprisingly-...

Iirc, Heisenberg reinvented Matrix calculations to solve a problem in quantum physics. Not being a mathematician, he wasn't aware of the concept. Born recognized what Heisenberg had done and introduced him to his own reinvention.

Lots of people working in different fields end up reinventing things that have been known to math for centuries, often in clunky roundabout ways. I imagine some of them figure out things not known to math, but it's far more likely to go the other way.

A lot of the time engineers are focussed with solving a problem, to build a working machine/program, while academics just want to publish.

This is also true with patents.