When you’re baking at home, for a few people, you can usually double the recipe and it will come out fine.
Quadrupling the recipe, however, rarely works. To get the same results you’ll need to adjust an ever growing list of variables. The extra pans will impact the airflow. The extra mass will change the heat distribution and baking times. As you scale, things like extra moisture will become problems.
Many SaaS Companies start off a lot like a baker working in a home kitchen. You can usually double everything and it will come out fine. Trying to quadruple the service introduces complex problems like concurrency, data loss, partial failures, and stale data.
Just as the transition from home to industrial kitchens has sunk many food startups, the transition from startup to scaleup has sunk many SaaS companies. If you can’t offer repeat customers consistency they won’t come back.