> No, not even at entry-level. 90% maintenance is a disaster. 60 to 75 percent might be typical for entry-level programmers, and that's bad, but 90 is abysmal.

In my experience and from what I've gathered from friends and coworkers over the years, ratios like that are actually quite normal.

And it doesn't have to do with entry-level vs. senior. I suppose a lot of HNers are working at tech startups or otherwise companies that build software-based products. But there's a lot of custom software out there (I'd say the large majority of running software as well as the large majority of software being written is custom, though I have no data to back that up). So lots of devs are either working in-house for non-software large companies, or working for companies that build custom software for such companies, and that usually entails a lot of maintenance work.