surprise surprise
I noticed this thread and feel a lot of empathy for those who have posted. I too have had similar situations.
I've been working for a number of years as an engineer (started working before completing my PhD). In my experience, there has been a noticeable decline in employer interest, when I list the PhD on my resume in an application to a developer job. I have been in the situation of needing to change jobs quickly, and I've really hit a wall when it comes to being perceived as overqualified. My job search has become most difficult at this point, and it's very frustrating.
Even after I removed the engineering PhD from the resume, I'm still having issues, even with work experience and a job currently. Engineering is apparently so vast of a field that job areas have become very niche. I've found that it's difficult even to move from the area of engineering I have experience with into another area that is "hot" and in greater demand. The best time to break into a new field is right out of undergrad, or right out of a graduate program if one has really no prior work experience.
I feel very stuck with my current line of work. My spouse is creating a lot of pressure for me to change fields into one that's more highly-paid and has better work/life balance. Doesn't sound entirely unreasonable, but doing this has become harder than it initially seemed. I don't want to get too personal about the situation, but it is really bothering me, in addition to my feelings of helplessness.
This situation has come as a big surprise to me after investing years in developing myself academically and professionally. My advice for anyone facing the same hurdle in their job search is: Stay motivated, and give a lot of attention to how you're marketing yourself with your resume. If you come across as too slated towards a specialized area of science or engineering, HR will likely toss your resume aside. Try to convey yourself as someone with a variety of general technical skills (e.g. software development, laboratory work, quantitative analysis). Pitch your dissertation project as a feat of project management. Highlight your presentation skills if you've spoken at scientific/technical conferences. Don't list publications, unless you're applying to research jobs. Computer skills are important, but try to limit what you to list in your resume to what may have broader uses in industry (programming languages and statistical compute packages). Summarizing yourself as a candidate with portable skills wanting to make a career transition at the top of your resume (below name, address of course) might not be a bad idea as well.
Hopefully this didn't come across as completely scattered, and who knows, maybe it will help someone. I wish everyone the best in their job search!