Why would you use RAG versus fine-tuning?

"I had a quick recruiter screen, then a really warm hiring manager round that started behavioral but got technical fast and felt more like a collaborative PM discussion than a formal interview. After that I got a 10-day take-home case in a completely different domain, and the full loop was a day-long panel where I presented it first and then met one-on-one with product, engineering, data science, and design. The most unusual thing was that they asked me to talk about myself as a person before the case, and it was clear they cared a lot about cultural fit and product mindset. I got the offer, but the final decision took close to a month because one panelist was out and the hiring manager kept me warm the whole time."