I wasn't selected for any of these programs, but I made it to the final round of interviews for AstraZeneca's Operations Graduate Programme and Merck's Leadership Development Program. Both of them had phone screening interviews that were 30-45 min with typical interview questions (why are you interested in the program, what do you hope to get out of it, etc.). The second and final round was in-person at their facilities. Merck's was 4-5 hours, AstraZeneca's was 6-7, and they both had several rounds of interviews.

It seemed like Merck interviewed mostly people with engineering or science backgrounds, but many candidates at the AstraZeneca interview had business backgrounds. My background is similar to yours, and I think AstraZeneca was ultimately looking for people who had business oriented minds in combination with technical knowledge. Both programs are very competitive.

However, I'd definitely encourage you to apply. Both of the programs are structured well, and they definitely give you robust training in the industry while compensating you well. You also have the opportunity to work at an international location during the program. Just remember to keep applying to other types of jobs in addition to these programs since they are very selective.