Scaling CI for monorepos: Challenges and how to overcome them

The article discusses the challenges faced when scaling a monorepo, which is a pattern where all application code is stored in a single repository. These challenges include managing an increasing number of developers working on the same repo, longer build times due to more code and changes, and limitations imposed by the speed of light for data transmission. The author presents three main challenges: dealing with too many people working in the same monorepo, exceeding capacity to build and test each change before merging into the main branch, and reaching a point where splitting the monorepo becomes more cost-effective than trying to maintain it as one large entity. The article also emphasizes the importance of measuring metrics to assess the effectiveness of solutions implemented for these challenges.