It took about 5 weeks in the design process, and there is literally a design for every resolution.
Since this was my first responsive project, I really had no clue on how to begin. The first week just involved me just researching other responsive websites, and thanks to a colleague I landed here: mediaqueri.es. Downloaded the css grid, so I knew what resolutions to work with.
My thought process for building the design went with starting out with maximum resolution, and then breaking it down into columns. The challenge was just getting that initial layout done, breaking it down wasn't as complicated as I thought it would be.