Tests absolutely cost time, inversely proportionate to the raw ability of the programmer. A 95th percentile engineer can write cowboy code with zero tests that

Tests absolutely cost time, inversely proportionate to the raw ability of the programmer. A 95th percentile engineer can write cowboy code with zero tests that largely works. Enforcing tests could cause up to a 50% slowdown. It’s probably worth it in the long run, but for a time and cash strapped startup its a legitimate cost/benefit analysis.