BTA CBDE case studies
BTA CBDE · Put your knowledge to work in context.
The Certified Blockchain Developer Ethereum (CBDE) is a vendor-issued credential from Blockchain Training Alliance (BTA) aimed at developers who build on Ethereum. BTA describes itself as training the world's leading companies since 2017 and offers enterprise training, self-paced courses, certification, and exam study guides through its site. The credential is best suited to programmers who already write code and want to demonstrate practical Ethereum development skill - Solidity contracts, development tooling, and application integration - rather than to non-technical learners seeking a general blockchain primer. Because the official CBDE page currently returns a 404 error, this page cannot confirm the exam's length, time limit, passing score, fee, retake rules, or validity period; those details should be verified directly with BTA before you register. The BTA CBDE case studies are 5 cases and about 2,682 words.
1Gas Cost of Storing an Audit Trail On-Chain
A team is building a provenance registry for a supply-chain pilot on Ethereum mainnet. Each product batch writes a record containing a 32-byte batch ID, a 20-byte manufacturer address, a 32-byte document hash, an 8-byte timestamp, and a variable-length UTF-8 note averaging 120 bytes.
571 words, about 3 min2Reentrancy in a Payout Queue
A Solidity contract lets users withdraw accrued rewards. The function reads the user's balance into a local variable, calls msg.sender.call{value: amount}("") to pay out, and only then sets balances[msg.sender] = 0 .
548 words, about 3 min3Hardhat vs Foundry for a Multi-Chain Deployment
A team of four developers is starting a DeFi protocol that will deploy to Ethereum mainnet, an L2, and a testnet. Two developers prefer JavaScript, two prefer Solidity.
536 words, about 3 min4Wallet Connection and Stale Reads in a DApp
A DApp shows a user's token balance and a pending reward. It reads the balance with a JSON-RPC call to a public endpoint and reads the reward from a contract event listener.
523 words, about 3 min5Coverage, Fuzzing, and a Mainnet Upgrade
A protocol has 92% line coverage in its unit tests and a green CI badge. It is about to upgrade a proxy that holds user deposits.
504 words, about 3 min