I've been working mostly in the payments domain for the last 16 years. 90% backend, 10% web frontend. So far, I've had write recursive code just once to conver

I've been working mostly in the payments domain for the last 16 years. 90% backend, 10% web frontend. So far, I've had write recursive code just once to convert SOAP requests/response to REST request/response on the fly so that the test cases that were written using SOAP client could be reused to test REST end point as well. To state the obvious, the chances of encountering recursive code depends on the domain. In my experience though a typical CRUD business app won't require a recursion as you pointed out. The examples you sited are mostly encountered in a "framework" code (e.g., Spring, some UI framework) and as is typically the case the number of developers "using" a framework is an order of magnitude more than those who implement/maintain them. Same is the case with compiler. On the other hand, those who deal with the lower level system code (OS Kernel, RTOS etc.,) shun recursion altogether to avoid its unpredictable stack need. So in the spectrum of developers the band of coders who frequently deal with or encounter recursion is quite narrow IMO. There are languages where recursion is the only construct available to deal with a collection of values so for those programmers recursive technique is a muscle memory. But I suspect there aren't as many professional users of such languages.