Data science or software engineering masters for CS PhD?

[Kao110]

Hi guys,

I wanted to ask a question about which masters I should do to prepare for a CS PhD. My options are Data science or software engineering. 

I am currently an RA in a top university in a cell bio lab, on my “gap years”. This school offers part time masters so I’d like to select the most appropriate masters to prepare for a PhD. My background is Biomedical engineering, with emphasis in mathematics. 

Thanks for the advise!