Signatures, idempotency, state machines, realtime push — details that fail silently and cost money rather than throwing errors.
The honest answer to 'does X take bitcoin' is usually a pattern, not a yes/no: some businesses accept directly, many via processors, and a large gray zone works through gift-card bridges. The living map of acceptance by pattern and industry, how to check any specific merchant in ten seconds, and why the list keeps growing.
Block intervals measured in production: Solana 376ms, Robinhood Chain ~0.1s, BNB Chain 0.45s, Base 2.0s, Ethereum 12.0s. What that means for the seconds your customer actually waits at checkout — and why detection architecture matters as much as chain speed.
A stablecoin transfer costs $0.0005 on Solana and $0.021 on Ethereum — a 44× spread, measured on our own production nodes, not copied from a fee tracker. The living dataset: per-chain costs for native and stablecoin transfers, the full methodology, and what the numbers mean for your checkout.
Most 'crypto subscriptions' are payment reminders in disguise. A breakdown of why recurring billing is hard on-chain — and how customer-funded vaults with welded terms finally make it real, non-custodially.
A webhook handler that works in testing can still lose money in production. These are the four failure modes worth engineering against before launch.