[rcheu]

It's pretty easy to do almost no coding at larger companies as a more senior engineer and become quite rusty. It sounds like he was interviewing for a position which he's actually expected to ship things and code, so it's pretty reasonable to ask him to code in the interview.

[astura]

Where have you worked where senior engineers do hardly any coding? What else would they do all day?! Are you sure you aren't thinking of project managers?

Everywhere I've worked (mostly large companies) the seniors write much more code than the juniors.

[pedrosorio]

Some senior engineers will be “coding machines” whereas others will be much closer to “architects” or “tech leads” where shipping a lot of code is not the most important aspect.

To be fair, most senior engineers should be involved in code reviews regularly, so it’s very unlikely they are incompetent coders.