My work used to be a smaller team. We had less than 13 devs for a while. We are now growing rapidly, and are over 20 with plans to be over 30 in a few months.

Our process for QA'ing and releasing each build is no longer working. We currently have everyone develop the new code, and stick it onto a staging environment. A few days before our weekly release, we would freeze the staging environment and QA everything. By our normal release time, everything was usually deemed acceptable and pushed out the door to the main site.

We reached a point where our code got too big so we could no longer regress the entire site each week in QA. We were ok with that, we just made a list of everything important and only covered that and the new stuff. Now we are reaching a point where all the new stuff each week is becoming too big and too unstable. Our staging environment is really buggy week after week, and we are usually 1-2 hours behind the normal release time.

As the team is growing further, we are going to drown with this same process. We are re-evaluating everything, and I personally am looking for suggestions / success stories. Many companies have been where before and progressed beyond, we need to do the same