Depending on your location, and preparation. My home office room (which also doubled as a workshop and light storage room) used to be 10' x 12', and I was able to sit with my back towards a wall, and my desk facing space. And it was in Brooklyn, NY, not an area known for cheapest sq.ft. It mostly depends on how you plan the room.
Being a software engineer usually gives you enough money to afford a nice desk if you care about it.
But not enough to afford an office room with enough space that one can put their desk facing space.
Depending on your location, and preparation. My home office room (which also doubled as a workshop and light storage room) used to be 10' x 12', and I was able to sit with my back towards a wall, and my desk facing space. And it was in Brooklyn, NY, not an area known for cheapest sq.ft. It mostly depends on how you plan the room.