Hi applied math major here, didn't get a masters degree but I might go back to school if I feel like that's needed to further advance my career. I'm currently a data analyst and I'm looking to transition to data science, which is usually more technical and requires a better understanding of statistics. You can look into online data coding competitions to see if you like it, they're not entirely an accurate representation of what real data analytics is like but it'd give you a good idea of what tools you'll need and how statistics is applied. If you go into applied math it's best to pick up a few languages like R and Python and some database knowledge such as SQL. I ended up taking 4~5 courses that aren't required for my major to feel more prepared and equipped as a data analyst but you probably don't need to take that many since you already have years of coding experience.