One of the most successful companies I worked at had no version control or unit tests whatsoever. The code was all maintained by one person (the company relied

One of the most successful companies I worked at had no version control or unit tests whatsoever. The code was all maintained by one person (the company relied heavily on custom software internally but it wasn't their product), who was able to keep the codebase small enough to basically hold in his head the whole time despite generating millions of dollars of value. That's certainly not how I would write code today, but it is amazing to see how much top-notch programmers vary.