But don't take my word for it: https://www.expatistan.com/cost-of-living/comparison/sofia/s...?
A decent full stack developer in his early 20s with no or little college education and 2-4 years of working experience is paid out 25,000 dollars yearly after all taxes and social contributions are paid.
Adjusting for living expenses that's like being paid out some $70-80,000 in the valley.
Developers here don't have debt, easily save up money, live in nice apartments, drive German luxury cars, enjoy 5-6 weeks of vacation where they travel to foreign countries. They meet in at 10 AM and leave at 6 PM sharp. We eat lunch together at restaurants every day and take plenty of breaks. From what I have experienced living 5 years here, life as a developer in Sofia (the most expensive city in Bulgaria) is more comfortable than in the Valley or New York.
Professional opportunities in the US are probably better, no doubt about that, but that's another story.