Gray-hairs, what criteria should a middle ager use to select a new job?

There is no right answer. At different times I have optimized for career growth (startup), compensation (FAANG), and currently work-life balance and flexibility (consulting). The only thing I would've done differently is that I didn't optimize for anything the first ten years or so, and jumped on whatever opportunity came knocking. Though in the end it all worked out well enough. So my first recommendation is to identify what matters to you most right now and don't second guess yourself - there is no perfect job out there. As soon as your priorities change and the current situation no longer works, switch.

The second bit of advice is to always push yourself out of your comfort zone. Embrace change. This might come off as trite, but that is how growth happens. Many people seem to find a comfortable groove (I did as well) and end up stagnating, and it can be hard to pull yourself out. Good luck!

I would actually filter first for who your manager is rather than the specific role. Your higher ups can make hard jobs easy, or make easy jobs hard. If you don't want to lose your grey hairs, this is the start.

Other than that, I would target management work for sure. Being familiar with the tech and implementation is important, but equally so is being a strong communicator. Management is an opportunity to strengthen that skill in different ways to what IC work allows.

Another avenue for the workaholic is founding a company. I'm not equipped to comment there though.

One thing that I realized way to late and kind of the hard way is that being an "IC" forever is not really realistic, and companies that say that you can, that they have a management track and a technical track are mainly lying.

Realistically, most dev positions only require, value, and will pay for like 5-10 years of experience, and will just churn through people in that range.

Even if you don't particularly want to be a manager, it's probably best to feign interest.

As a middle ager, you want two things: to stay relevant for the foreseeable future, and freedom to control your time.

Those would be my optimisation suggestions. You need to stay in a technology trajectory that will have utility into your 60s, and you want time to work on your own projects and potentially raise a family or find a mate, or whatever is your personal life goal.

It depends on you. Do you want to work in the comfort zone of your expertise from the past or do you want to learn new things to push your knowledge base. For me, I have to learn something... something... every day

Are they really hiring? Is the company healthy or about to go under? Will the pay and benefits be enough for you and any dependents to survive? Are they assholes or criminals or both? Are there opportunities for growth?

I'm 51. An 80 year old told me the third job is the good one.

Does it provide a healthy (physically and emotionally) path to financial independence and ability to retire, sooner rather than later?