My response times might be overestimated here with 3 mentions in less than 8 hours
First off, switching between CS and DS is drop dead easy, and many classes are shared, so the good news is that indecision is very much okay here! I’d say that the “how” of this will likely be covered in the second and third semester sof classes more than anything I or anyone else can say on this forum!
For Northeastern specifically, there are actually two DS intro paths, and one shares with CS, so no matter what, make sure to start there with CS2500 (Fundies 1) which is a unique course in the curriculum (see Developing Developers) for more on why. The DS path would be for someone who knows with 100% certainty they want to do DS. So in terms of coursework, there will literally be no difference in the first semester.
Even within the CS degree there are different concentrations (AI, Systems, Theory, Software) though there’s a lot more time to choose there. The cybersecurity program is actually its own degree rather than a concentration, though it shares a good deal of classes.
With that said, here’s how I’d personally differentiate:
CS is for people who like building things, whether that be apps, platforms, operating systems, tools, etc. You will likely want to have some product interest in what that thing you’re building is.
DS is for people who like to study things to draw conclusions. It uses programming, but mainly as a gateway to math and statistics work that then informs the decisions that CS (or people in general) use to make decisions. It’s less about making the decisions than providing the best information possible to make the best decision.
At the technical level, DS is more mathy / conceptual and CS is more about “design”. So stronger math students will probably enjoy DS more, speaking in generalities.
With those, it’s really just guess and check. I wouldn’t be worried about the flexibility leading to giving up given that the starting path is what’s actually shared, and neither path is easier than the other objectively. You’ll really only know for sure by doing. The program is not designed to weed out either. You may even find doing a co-op in each is worthwhile to see! Doing extracurriculars in both is another good way to try and see what fits best.
I do generally recommend people start with CS though, as it’s the “umbrella”. It’s a bit easier as you go down the path to go CS to DS than DS to CS from a mental perspective IMO. Same goes with CS to cybersecurity. IMO those immediate specializations are for people who are confident in it. The mere sign that the flopping has happened to me is a sign to stick with CS for now and then let it take its course from there