[s2th4d]

It's unclear to me what kind of position/stack you are applying for. But I would say if you're finding "pretty advanced calculus problems" in your interview coding challenges, that you may either be applying for positions that require that kind of mathmatic thinking, or the companies themselves do not know how to select relevant gate problems for hiring candidates. It's probably a bit of both, but I would take those as signs that maybe they aren't the kind of company that you want to work for. I have only been a dev professionally for 4+ years, but can say I've been on the other side as the interviewer. The LeetCode/HackerRank hiring code challenges are not without their flaws, but at the same time, there is necessity for assessing candidate's skills in problem solving and their ability to work through coding challenges.

Honestly, someone who is 16 years deep in their software dev/eng. career I would expect to utilize their contact network to find potential jobs above relying on coding challenges and applications. I would expect you to be a Senior level dev who can orchestraste teams and a bit of product/project mangement, if in addition to working on code yourself, demonstrating system and software architecture level prowess and aptitude. These are not so much things that can be solved mathmatically/programattically in a coding interview per ce, unless a hyper-focused chunk is being used as the challenge. But I'm just in the peanut gallery... My advice is to use your network and taylor your resume, use a resume service if you need to -- they can be 3x-10x their weight in making you more attractive as a candidate, as well as perhaps take a new approach towards finding positions to apply to.

Maybe even reach out to people in the past you have worked with and let them know you are looking, and if you have positions you are applying to, pass them the link to the job description and ask if these seem like descriptions of a job that would be appropriate for you. As introverted as so many of us are, we tend to think that we should know how to do everything ourselves. Sometimes, if not many times, we need another set of eyes and perspective on our approach.