the leetcode/algo question stuff is mentioned here on HN alot but I've never gotten to the point where a test was actually offered to me. will start practicing though and hopefully an opportunity pops up.
If you're not getting calls, it's your resume that is bad. That either means the format, or the content. Seems to me the only change to the content that you can make is working on and advertising well written open source personal projects that your interviewers can see, or contributing to large open source projects.
Your resume should be exactly 1 page long, and have something that stands out (company worked for, open source contributions, volunteer work.. anything that makes it be different).
If you have worked for decades, write "over 10 years experience" :)
Bullet points are good, long sentences are bad.
Listing tech/languages is a good idea if you can list a lot of real stuff. No one cares if you used ms word.
It should be 1 page!!! Don't cheat via small fonts. People can look at your linkedin if they need to know all that crap.
In that case, you might want to have a friend/acquaintance with a job like what you want to review your resume and give you feedback on that and a first round-style interview. If you don’t know anyone who can, read over resumes on linkedin, and pay close attention to the language used, and to the extent that it’s relevant to your work try to mirror it. Try to be direct and confident about what you know/don’t know during the interview, and try to at least learn how to talk about technologies that touch what you’re more expert in.