First, a take-home coding question (using Codility), then one phone interview, then two more phone interviews.

The last two interviews, I was told, would be over Skype, and I was told that I would need access to a computer. In reality, only one of the two interviewers called me on Skype, and even that was without video. The second one called me on the phone. None of the two required access to a computer. Turns out, I didn't have to carve out the time slot with computer access; I could have done everything over the phone. Time wasted.

All technical questions were at a high school level, but non-technical ones were relatively okay (see next section).

After rejecting me, they didn't want to explain why. Generic terms like "not fit" were used. When pushed for specifics, they explicitly said that they wouldn't tell.

This is puzzling, for I answered all technical questions correctly (they were extremely easy), and I answered non-technical questions confidently, from real and successful past experience.

From their own admission, their codebase has tons of technical debt, and they are "trying" to migrate forward. Yet, the technologies to which they are migrating are already outdated by several years.

Half of the staff, by their own admission, consists of people who are "not very excited" about migrating to newer technologies. With two of these people I actually spoke, and it's true: they both have been in software for decades, yet know only one design paradigm and two to three programming languages.

Technical:

What is a garbage collector? How do you concatenate a list of strings in .NET? What kinds of collections are available in the standard .NET library?

Non-technical:

Teach me a thing that you're excited about. How would you push a new technology/platform that you're sure is right?