This is a great example of the difference between software development and production engineering.
Most developers spend their early years asking, "How do I make this work?" Eventually the question becomes, "What happens when it stops working?" That's where reliability starts.
The point about failure paths stood out the most. Many systems are designed around successful requests, but production environments are defined by timeouts, dependency failures, traffic spikes, bad user behavior, and unexpected edge cases. The teams that plan for those scenarios usually ship more resilient products.
I also agree that deployment is often misunderstood. Launching code is relatively easy. Monitoring it, maintaining it, and continuously improving it under real-world conditions is where most of the work actually begins.
One thing we've seen while helping startups build products at Foundersbar is that reliability practices don't need to wait until enterprise scale. Feature flags, observability, caching, rate limiting, and clear rollback strategies provide value much earlier than most founders expect.
A useful reminder that users don't care how elegant the architecture is. They care that the product works consistently when they need it.