Is this a screening call where you are grilled with tech questions? Or is this an initial chat where both sides share what they’re looking for in a candidate/you say what you want in a position?

It's being hosted by the company's recruiter, so I'm assuming it's more of an initial chat.

If you’re just chatting with the recruiter, not much to prepare… Just be a genuine person, and try to learn more from the recruiter as well. Don’t take rejection too hard at this level. There’s so many factors at play, ranging from recruiter quality to how this company hires that may preclude a more junior person.

Also line up more calls :). The recruiter themselves is probably playing a numbers game for the role. There’s a lot of opportunity out there. The other career switcher I knew hunted for some time before finding a role somewhere that explicitly mentored and grew people in an academy of sorts.

I will try to relax and just be inquisitive then, thank you :) I think I have prepared enough today lol

I'd recommend writing down questions that the recruiter asks and then preparing for them for future interviews. Even at a more senior level, the initial chat questions are the same. You shouldn't memorize lines, but it sucks when you get caught by another, "What's your biggest weakness?"

From other comments it sounds like its an initial call.

Something to think about is how your background in being a chemist can relate to software. Do you see similarities with how things are structured chemically and how you build programs? Are there analysis and debugging skills that can help you as a programmer? I'll also assume there is a fair amount of statistics used in the sciences which is helpful when working with applications that have decent traffic.

Good Luck!