"Works fast" vs "Capable to serve"
Many of developers have a strong believing — faster is better. It's not universal truth.
The fact that you can achieve faster execution in development environment under moderate workload doesn't mean you achieve more capacity, more ability to serve users. You may be faced with:
- Resource contention in parallel execution.
- Unscalability for some technology piece.
- Higher cost to scale with technology working fast than with technology working ok.
Basically, speed in not "the more the better" quality aspect for customers. Speed have to be good enough or more than enough for some degree.
Often, not speed, but capacity limits businesses from growth.