Many things at Twitter were broken to the point that they could bring the entire site to a halt. Greg’s strategy, now distorted through multiple retellings and my own foggy memory, was to focus on short-term triage rather than long-term fixes.
Essentially, he realized that a collection of temporary, duct-taped fixes was the only thing that would give the Twitter team the breathing room to start working on longer-term fixes.
I think of this in school grade terms. Greg went looking for all the Fs and then turned them into Ds. Then he turned all the Ds into Cs and then all the Cs into Bs, etc.