Looking at https://imgur.com/a/eTphrRF
The code that he writes is a blend of languages. The arrow operators -> is indicative of C/C++ but C/C++ doesn't use nil or function. It's like he thinks in C/C++ first which puts him at about my age mid-40s. Anyone younger than 40 would be using dots '.' due to Java/Javascript/Python instead of '->'. Does anyone else get that vibe?
Wouldn't say that, I'm around 30 and grew up coding C, C++ and later, in my teens some Perl anf PHP, all these languages use the -> syntax and I still used that in my notes up until two or three years ago, I also use nil from my lisp adventures and prefer snake_caas. The first languages have I learned as a young child made an strong impression in my mental visualisation of programming concepts even of I haven't used them in many years. I found notes on my iPhone using the arrow syntax with snake_case variables. And from the pictures he looks about my age so I'd say 30 is a real possibility as well.
A lot (I would be surprised if it's not the majority of EEs/CpEs) of electrical/computer engineers are taught how to program with C/C++; using that to understand what age someone is, is an error.
Based on the "being in tech for about a decade" his "initially looks old with the beard but has young looking eyes" and your comments here, I'd put him squarely in his 30s.
I've just hit 30 and I still default to C or C-style to think about code. I've been formally taught coding with the K&R (while being introduced to Perl, Bash, PHP and LUA as a teenager), and I'm far from the only one.
Some colleges teach courses with C++, and if students or young programmers want to get into game development or graphics, they're often recommended to pick up C++. Systems programming is often taught using C++, if not C.
