Nobody runs a validator to read a balance: apps query RPC endpoints — public ones that are free and crowded, or dedicated providers you pay for rate limits and uptime. 'The chain is fine but the RPC is down' is the most common 'blockchain outage' in practice.
Production setups treat it like the dependency it is: primary plus fallback providers, retries with backoff, health checks, and alerts that fire before users notice. A write path that can switch providers mid-incident is the difference between a blip and a frozen checkout.
Related terms
Solana
A high-throughput, low-fee blockchain — thousands of transactions a second at fractions of a cent — built for applications that need speed.
On-chain
Recorded on the blockchain itself — permanent, public, verifiable by anyone — as opposed to off-chain data in someone's database.
Rate limiting
A control that caps how many requests a client can make in a time window — the basic defence against brute force, scraping, abuse and runaway API costs.
The bench this belongs to
BlockchainSolidity on Ethereum, Polygon, Base and Arbitrum. Anchor programs on Solana. Written with tests first, because a redeploy is not a hotfix once value is on the line.
