How did you become an ML Engineer without a technical background?

I would first ask the question of why machine learning, just like I would for why video games, or why react.

If you are trying to learn it solely because it is popular and you just want a job, then you have a few problems: competing with others, understanding the inherent needless complexity in the tech, and ultimately what to do if the tech wanes in popularity.

If you are learning it because you genuinely love the tech and want to spend the rest of your career doing it (which is how I feel about Java but not about video games), then you will be able to persevere through the challenges that come your way.

Now, to answer your real question: "what will interviewers think about my lack of a technical background". My real answer to this is that this industry is broken, most people are lying, most people have an ego, most people are biased and operating arbitrarily.

Your resume needs to somehow get you the interview, your background needs to be good enough or doctored enough to placate them, and then you need to blow them away with the quickness and sharpness of your answers to their technical questions.

No amount of PHD work or real world knowledge can ever guarantee that you will pass an interview. It's total luck of the draw and the interviewer's bias around how serious they are about hiring somebody.

Good luck!

So there's definitely opportunities for taking on a role as an ML engineer with a non traditional background.

From a learning perspective, I'd say that you could start by taking courses on statistics and probability, then reviewing a little bit of calculus, and then doing something like the machine learning and deep learning courses on coursera.

From there you can test out your skills using a platform like https://workera.ai/

For getting raw experience though -- if you aren't in an academic setting, or a technical setting where you could be exposed to those opportunities, the best thing that you can do is contribute to widely used ML libraries on a platform like github. It's definitely not easy to get started in that process, but it'll teach the workflow of a basic ML or research SWE, and you will definitely be a super independent learner or worker after that.

Good luck with your journey!

Why would someone consider machine learning without a technical background?

It's like saying how did you become a doctor without med school?

What is your motivation ? That's a real question and you should start there. If you find the right motivation, hard things become within reach.