Blockchain Developer Decentralized Application (dApp) Architecture 2

Question 1

In a typical dApp stack, what role does the smart contract layer primarily serve?

Accepted Answer

Backend business logic and state on-chain

Answer

Client-side rendering

Answer

DNS resolution

Answer

TLS certificate management

Question 2

Which library is most commonly used by a dApp frontend to interact with an EVM blockchain?

Accepted Answer

ethers.js

Answer

jQuery

Answer

Lodash

Answer

Bootstrap

Question 3

Why are decentralized storage systems like IPFS used in dApps instead of storing files on-chain?

Accepted Answer

On-chain storage is expensive and limited

Answer

IPFS is faster than RAM

Answer

Blockchains cannot store text

Answer

IPFS encrypts automatically

Question 4

What does a wallet like MetaMask provide to a dApp architecture?

Accepted Answer

Key management and transaction signing

Answer

Smart contract compilation

Answer

Block production

Answer

Database indexing

Question 5

Which component lets a dApp efficiently query historical and aggregated on-chain data?

Accepted Answer

An indexer like The Graph

Answer

A raw JSON-RPC eth_getBalance call

Answer

A CSS preprocessor

Answer

A CDN edge cache

Question 6

What is the purpose of an ABI in dApp architecture?

Accepted Answer

Defines how to encode/decode contract calls

Answer

Stores private keys

Answer

Compresses block data

Answer

Routes peer connections

Question 7

A 'trustless' dApp means users must trust which of the following?

Accepted Answer

The deployed contract code and chain consensus

Answer

A central admin server

Answer

The frontend host's database

Answer

The wallet vendor's cloud