Future: web3 trade-offs
This course covers how to evaluate a proposal to put part of a product on a blockchain. It names the one property a chain provides: shared state among mutually distrusting parties with no trusted operator. It states the strongest case for it, then prices it: latency, throughput, per-write cost, finality, lost keys, the right to erasure under GDPR and LGPD, and node operations. It closes with the three fits that survive, the split between chain and Postgres in a Rails app, and an ordered list of review questions.
What you'll learn
- ✓Name the property a blockchain provides that a database does not
- ✓Test a proposal by naming the distrusting parties and checking for an acceptable operator
- ✓Compare latency, throughput, per-write cost and finality against Postgres
- ✓Weigh key loss, custody, erasure under GDPR and LGPD, and node operations
- ✓Split data between the chain and Postgres, with an indexer and a state machine in Rails
- ✓Review a proposal in order and recognise answers that end the conversation
The one thing a chain gives you
Someone opens a planning meeting with "we should put this on chain". The room splits into two useless halves. One half is enthusiastic and can't say what problem it solves. The other half rolls its eyes and can't say why it won't work.
Read the full lesson free →Curriculum
7 lessonsThe one thing a chain gives you
Defines the one property a chain offers and explains why the honest default for most products is no.
The case, made properly
Makes the strongest case: reconciliation between distrusting organizations, bearer assets and provenance checked by someone other than the operator.
The question that kills most proposals
Asks who the distrusting parties are and whether an accepted operator exists, and shows the append-only table alternative.
The bill: latency, throughput, finality
Compares chain latency, throughput and auction-priced writes with Postgres, and treats finality as a correctness concern.
The bill: keys, erasure and nodes
Prices user-held keys with no recovery, custody, immutability against GDPR and LGPD erasure, and the cost of running nodes.
Where it fits, and what stays in Postgres
Lists three fits that survive, what goes on chain, and why an indexer and Postgres remain in Rails.
Evaluating a proposal you were handed
Gives eight ordered questions for reviewing a proposal, the answers that end it, and how to say no.