[jkingsbery]

I do a fair amount of helping interview senior positions at my current company. At the risk of saying something obvious: when interviewing senior people, the goal is to figure out whether they will do well operating at a senior level. Senior engineers usually bring two things to a team: a broader and deeper technical knowledge, and the ability to help influence and structure larger projects (doing larger scale designs, reviewing designs and code from other engineers, helping mentor more junior engineers, things like that). Side projects can sometimes help inform someone's technical abilities, but it's rare for people to have a side project where they are doing a lot of the "influencing others" part of the job.

But, yeah, if you put in the work, it shouldn't hurt to list your side projects. But also, keep them in perspective: don't bring them up simply because they would be "interesting to discuss." By their nature, side projects don't deal with a lot of challenges of professional projects: there's usually no deadline, there's no disagreements with other engineers, they deal with a smaller scale audience so don't deal with bugs and maintenance.