LearnThatStack Ace your next interview
Blockchain Technologies
Ethereum.
30 Qs 4 free
Change topic Change
Drill · questions

All questions

of 30
Beginner 9
01

What is Ethereum and how does it differ from Bitcoin?

Beginner ·

Answer it yourself first - out loud, or typed below.

How should your speech become text?

Listening… your words appear above as you speak - tap Stop when you're done.

Recording · cr - tap Stop & transcribe when you're done.

Transcribing with AI…

Voice:

Keep going - a few more words and AI can grade it.

Last attempt -

Your answer

Re-explain

Ethereum is a decentralized blockchain platform that enables the creation of smart contracts and decentralized applications (DApps). While Bitcoin is primarily a digital currency focused on peer-to-peer transactions, Ethereum is a programmable blockchain that acts as a "world computer."

Key differences:

  • Purpose: Bitcoin is digital money; Ethereum is a platform for decentralized applications
  • Programming: Ethereum is Turing-complete with its own programming language (Solidity)
  • Virtual Machine: Ethereum has the Ethereum Virtual Machine (EVM) for executing smart contracts
  • Gas System: Ethereum uses gas to measure computational work
  • Block Time: Ethereum has faster block times (~12 seconds vs Bitcoin's ~10 minutes)
Rewriting in plainer words…

This answer doesn't lend itself to a diagram - it reads best . No credits were charged.

The model's verdict: “

The interactive diagram is below the answer - jump to diagram ↓

This answer is explained by a shared concept diagram - open

Tailored explanation · switch back to · ·
Point the redraw:
How well did you know this?
AI:

02

What is a smart contract?

Beginner ·

Answer it yourself first - out loud, or typed below.

How should your speech become text?

Listening… your words appear above as you speak - tap Stop when you're done.

Recording · cr - tap Stop & transcribe when you're done.

Transcribing with AI…

Voice:

Keep going - a few more words and AI can grade it.

Last attempt -

Your answer

Re-explain

A smart contract is a self-executing contract with terms directly written into code. It automatically executes when predetermined conditions are met, without requiring intermediaries.

Key characteristics:

  • Immutable: Once deployed, code cannot be changed (unless designed with upgradability)
  • Deterministic: Same input always produces same output
  • Autonomous: Executes automatically when conditions are met
  • Transparent: Code is publicly visible on the blockchain

Example use case: An escrow contract that automatically releases funds when both parties confirm completion of a service.

Rewriting in plainer words…

This answer doesn't lend itself to a diagram - it reads best . No credits were charged.

The model's verdict: “

The interactive diagram is below the answer - jump to diagram ↓

This answer is explained by a shared concept diagram - open

Tailored explanation · switch back to · ·
Point the redraw:
How well did you know this?
AI:

03

Explain the concept of decentralization in Ethereum.

Beginner ·

Answer it yourself first - out loud, or typed below.

How should your speech become text?

Listening… your words appear above as you speak - tap Stop when you're done.

Recording · cr - tap Stop & transcribe when you're done.

Transcribing with AI…

Voice:

Keep going - a few more words and AI can grade it.

Last attempt -

Your answer

Re-explain

Decentralization in Ethereum means that no single entity controls the network. Instead, it's maintained by thousands of nodes worldwide.

Three types of decentralization:

  • Architectural: No single point of failure (distributed nodes)
  • Political: No single person/organization controls the system
  • Logical: Shared state and protocols across all participants

Benefits include censorship resistance, reduced single points of failure, and increased security through distributed consensus.

Rewriting in plainer words…

This answer doesn't lend itself to a diagram - it reads best . No credits were charged.

The model's verdict: “

The interactive diagram is below the answer - jump to diagram ↓

This answer is explained by a shared concept diagram - open

Tailored explanation · switch back to · ·
Point the redraw:
How well did you know this?
AI:

04

What is Ether (ETH) and what are its primary uses?

Beginner ·

Answer it yourself first - out loud, or typed below.

How should your speech become text?

Listening… your words appear above as you speak - tap Stop when you're done.

Recording · cr - tap Stop & transcribe when you're done.

Transcribing with AI…

Voice:

Keep going - a few more words and AI can grade it.

Last attempt -

Your answer

Re-explain

Ether (ETH) is Ethereum's native cryptocurrency. It serves multiple purposes:

  • Gas fees: Pay for transaction execution and smart contract operations
  • Staking: Validators stake ETH to secure the network (Proof of Stake)
  • Store of value: Digital asset for investment and savings
  • Medium of exchange: Payment method in DApps and DeFi protocols
  • Unit of account: Pricing mechanism for tokens and services

ETH is divisible to 18 decimal places, with the smallest unit called "wei" (1 ETH = 10^18 wei).

Rewriting in plainer words…

This answer doesn't lend itself to a diagram - it reads best . No credits were charged.

The model's verdict: “

The interactive diagram is below the answer - jump to diagram ↓

This answer is explained by a shared concept diagram - open

Tailored explanation · switch back to · ·
Point the redraw:
How well did you know this?
AI:

05

What is Solidity and why is it used for Ethereum development?

Part of Pro
06

What is a constructor in Solidity and when is it executed?

Part of Pro
07

What is gas in Ethereum and why is it necessary?

Part of Pro
08

What is the difference between mainnet, testnet, and private networks?

Part of Pro
09

What are the main tools used in Ethereum development?

Part of Pro
Intermediate 15
10

What is the Ethereum Virtual Machine (EVM)?

Part of Pro
11

Explain the difference between `view`, `pure`, and `payable` function modifiers.

Part of Pro
12

What are events in Solidity and why are they important?

Part of Pro
13

Explain the difference between `storage`, `memory`, and `calldata` in Solidity.

Part of Pro
14

Explain the difference between gas limit and gas price.

Part of Pro
15

What happens when a transaction runs out of gas?

Part of Pro
16

How do you optimize gas usage in smart contracts?

Part of Pro
17

What is the difference between Ethereum 1.0 and Ethereum 2.0?

Part of Pro
18

Explain Proof of Stake vs Proof of Work in the context of Ethereum.

Part of Pro
19

What are Ethereum nodes and what types exist?

Part of Pro
20

What is DeFi (Decentralized Finance) and how does it work on Ethereum?

Part of Pro
21

Explain what an ERC-20 token is and its standard functions.

Part of Pro
22

What is the difference between ERC-20, ERC-721, and ERC-1155 tokens?

Part of Pro
23

Explain the concept of slippage in DeFi and why it matters.

Part of Pro
24

How do you test smart contracts effectively?

Part of Pro
Expert 6
25

What is a reentrancy attack and how can it be prevented?

Part of Pro
26

What are some common smart contract vulnerabilities?

Part of Pro
27

What are Layer 2 scaling solutions and how do they work?

Part of Pro
28

What is sharding and how will it improve Ethereum scalability?

Part of Pro
29

What is Maximum Extractable Value (MEV) and how does it affect Ethereum?

Part of Pro
30

Explain the concept of composability in DeFi (often called "Money Legos").

Part of Pro

No matches

Try a different filter or search term.

Pro · $10/mo

26 of 30 Ethereum answers are gated.

Full answers, code samples, AI explanations - simpler, deeper, or as an interactive diagram. Cancel anytime.

  • Full answers + code
  • AI explain - simpler, deeper, or visualized
  • 1,000 AI credits / month
  • Cancel anytime

Change topic

Pick a different technology or stack. Your current topic stays put until you choose a new one.

Technologies
No technologies match “”.
Cross-cutting topics
No topics match “”.
By role
Stacks & frameworks

MEAN

MongoDB, Express, Angular, Node.js

MERN

MongoDB, Express, React, Node.js

LAMP

Linux, Apache, MySQL, PHP

Django

Python Full-Stack Development

Ruby on Rails

Convention over Configuration

JAM

JavaScript, APIs, and Markup

Serverless on AWS

Serverless Architecture on AWS

Cross-cutting topics 43 topics

Interviewers also test these - they're common to every stack, whichever one you picked above.

Flutter Mobile

Flutter Cross-Platform Mobile Development

Cross-cutting topics 44 topics

Interviewers also test these - they're common to every stack, whichever one you picked above.

Spring Boot

Enterprise Java Development

.NET

Microsoft Ecosystem

Vue

Vue.js, Vite, TypeScript, Tailwind, Node.js

Go Backend

Golang, gRPC, PostgreSQL, Redis, RabbitMQ

FastAPI

Python, FastAPI, SQLAlchemy, PostgreSQL

React Native

React, TypeScript, Redux, Firebase

iOS Native

Swift, SwiftUI, UIKit, Firebase

Android Native

Java, Jetpack Compose, Firebase

Web3 / Ethereum

Solidity, Ethereum, Hardhat, Foundry

DevOps / Platform

Docker, Kubernetes, Terraform, CI/CD

Core SWE Interview Prep

Data structures, algorithms, OS, concurrency, networking, git
Big-O & Complexity Analysis Arrays, Strings & Hash Tables Linked Lists, Stacks & Queues Trees, BSTs & Heaps Graphs Sorting, Searching & Recursion Operating Systems Concurrency & Multithreading Networking for Developers Git & Version Control API Design 45 Distributed Systems Fundamentals 34

Cross-cutting topics 43 topics

Interviewers also test these - they're common to every stack, whichever one you picked above.


Cross-cutting topics 45 topics

Interviewers also test these - they're common to every stack, whichever one you picked above.