The short answer
Blockchain is the right tool when multiple parties who do not trust each other must agree on shared state without a trusted intermediary. If one organisation controls the data, a database is faster, cheaper, and easier to fix. That test eliminates most proposals before the technical discussion starts.
The test, in three questions
- Are there multiple writers?: If one party writes all the data, you do not need consensus — you need a database with an audit log.
- Do they distrust each other?: If they trust a shared operator, that operator can run a normal system far more cheaply.
- Does the record need to be verifiable without that operator?: This is the question blockchain uniquely answers. If the answer is no, you have a database problem.
Where it genuinely fits
- Decentralized finance, where the point is that no institution is the counterparty.
- Provenance across organisations that compete but must share a ledger.
- Settlement between parties without a clearing intermediary.
Exec9 has shipped in this space — UniLabs is an AI-powered decentralized finance asset management platform built on Ethereum and Solidity.
The honest cost
On-chain state is expensive, slow relative to a database, and public by default. Smart contract bugs are frequently unfixable after deploy. Those are acceptable costs when you genuinely need trustless verification, and pure overhead when you do not.