Metric Value Firebase cost increase at scale 300-500% per year User threshold for migration 5-10 million active users Average migration timeline 6-12 months Firebase attracts startups with generous free tiers and simple APIs. The Spark plan offers 10GB storage, 1GB daily downloads, and 50,000 daily authentications at zero cost. This covers most MVPs for 6-12 months. The pricing structure seems transparent until you hit scale. The Blaze plan charges $0.18 per GB stored, $0.12 per GB downloaded, and $0.06 per 100,000 function invocations. A startup with 100,000 daily active users typically generates 500GB monthly downloads, 50 million function calls, and 200GB storage growth. That's $1,460 monthly before considering Firestore operations, which add another $0.36 per million reads and $1.08 per million writes. Real cost explosions happen with poor architecture decisions made early. One e-commerce startup saw bills jump from $500 to $15,000 monthly after implementing real-time inventory tracking.…