As a Software Consulting Company we find ourselves battling the question of how to scale while ensuring the quality level is always the same.
Here is how we plan to solve this:
We hire people who are passionate about the work they do. We also ensure they are opinionated but without egos. This makes it easy for them to quickly pick our style and deliver software that adheres to our quality standards.
We have style guides for each frameworks we work with. This has all the do's and don'ts that programmers should follow. At the end of the day code is our medium of communication and having this style guide ensures everyone is speaking the same dialect.
We follow git-flow. More on this here