This comment reads as full of hubris. It is easy to say you can do what someone else does, but the fact is you haven't done it, don't have the evidence to show

This comment reads as full of hubris. It is easy to say you can do what someone else does, but the fact is you haven't done it, don't have the evidence to show that you can, and are exasperated that others don't see in you what you see in yourself. Having a PhD in a relevant field is an objective signal - not proof - of capability. When these jobs are hot and candidates are plentiful, using signals to narrow the field to a group you can more rigorously interview is typically a more effective use of time than buying into everyone's self-belief. Candidly, I find most individuals from a programming background vastly underestimate the skillset required in this space. I know that is not an uncommon perception and you are likely being penalized for it, fairly or unfairly. I'll say this: anyone who refers to data science as "just linear algebra and calculus" would be immediately removed from any candidate pool I was managing. Others have evidence of capability, you do not. Programming experience is not evidence enough to elevate you above candidates with more reliable and relevant credentials. A shelf full of books is not evidence either. You either need to find a version of this job created by people that don't really know what it is they want (hint: if the Data Science JD says "Excel" that's an indicator, it's not too uncommon) to create a work history, find a way create a portfolio that you can use as evidence (e.g., Kaggle competitions, hobbyist projects with available datasets), or network with others in the industry and academia such that they will vouch for you.