Home
Channels
Blockchain Quiz

Blockchain Quiz

quiz

Blockchain quiz for job seekers: test smart contract, Solidity, DeFi, security and Web3 fundamentals with answers to prepare for technical interviews.

Blockchain Quiz Medium

Time limit: 10 sec Best 1.928s

What is the main goal of a SubDAO?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
CryptoCoder_AJ @CryptoCoderAJ

1.928s Time to beat

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 2.375s

Why do Web3 BDs need SQL skills?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Jeevesh Kuril @jeeveshk

2.375s Time to beat

Second place
FintechLee @FintechLee

5.987s

Third place
hao qin @peaceful-pebble

6.733s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 1.672s

What is Dune Analytics primarily used for?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Abdil Hamid @ForensicBlockSmith

1.672s Time to beat

Second place
CryptoCoder_AJ @CryptoCoderAJ

2.299s

Third place
Kaustubh @kaustubh

2.914s

Place 4
Jeevesh Kuril @jeeveshk

3.909s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 0.778s

What is the core risk of using tx.origin for authorization?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Kaustubh @kaustubh

0.778s Time to beat

Second place
Tushar Dubey @DataChainTushar

1.912s

Third place
Hamed Mohammadi @spry-snorkeler

5.093s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 2.358s

In a 30-second portfolio audit, which commit message signals production-grade engineering hygiene?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Natalie Reed @WillowSyncDev

2.592s Time to beat

Second place
Merry Thomas @Merrythetechie

3.184s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Hard

Time limit: 15 sec Best 1.629s

A Cloud/IAM security engineer wants to transition to Web3. Which portfolio artifact proves the highest hiring value to a founder?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
CryptoCoder_AJ @CryptoCoderAJ

1.629s Time to beat

Second place
Natalie Reed @WillowSyncDev

3.039s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 1.048s

What makes a blockchain developer project recruiter-readable?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Alex Chen @AlexC

1.048s Time to beat

Second place
nithin sureddy @jolly-artist

1.509s

Third place
Emma Thomas @emmathomas

2.109s

Place 4
Natalie Reed @WillowSyncDev

2.551s

Place 5
Hrushi G @hrushigawade6

4.050s

Place 6
Akshay Deore @akshu

4.345s

Place 7
Prathmesh Aghao @fresh-helper

6.984s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 1.252s

What is the most direct risk of “unbounded loops” in on-chain code?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Wasim Choudhary @K9QfAg6

2.575s Time to beat

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec

Which audit signal indicates poor threat modeling?

Get it right. Claim the #1 spot.

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

Get it right. Claim the #1 spot.

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 2.261s

What’s the strongest proof for blockchain developers in hiring?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Hrushi G @hrushigawade6

3.136s Time to beat

Second place
Ahmad Abubakar @mellow-vada

4.511s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 0.000s

Which bug class is most associated with incorrect upgradeable storage layout?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Hamed Mohammadi @spry-snorkeler

1.635s Time to beat

Second place
Rahul Kumar @tachy-balloon

6.702s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 0.263s

Which keyword prevents a state variable from being modified after deployment construction?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
SmartContractGuru @SmartContractGuru

0.263s Time to beat

Second place
DeFiArchitect @DeFiArchitect

0.951s

Third place
Shubhada Pande @ShubhadaJP

1.449s

Place 4
Andria Shines @ChainSage

1.714s

Place 5
Tushar Dubey @DataChainTushar

1.764s

Place 6
Lydia Ahenkorah Gyamfi @BWN3f48

2.508s

Place 7
Priya Gupta @CryptoSagePriya

3.850s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec

Which storage type enables EIP-1167 minimal clones to be cheap?

Get it right. Claim the #1 spot.

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

Get it right. Claim the #1 spot.

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 1.736s

Which pattern most directly reduces reentrancy risk on external transfers?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Anita Patel @SmartContractSensei

1.736s Time to beat

Second place
Lydia Ahenkorah Gyamfi @BWN3f48

3.292s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 6.708s

In EVM, which opcode can silently fail and return a boolean instead of reverting?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Lydia Ahenkorah Gyamfi @BWN3f48

6.708s Time to beat

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 9.942s

Which audit issue is most often downgraded incorrectly?

Get it right. Claim the #1 spot.

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

Get it right. Claim the #1 spot.

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec

Which finding has highest real-world exploit probability?

Get it right. Claim the #1 spot.

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

Get it right. Claim the #1 spot.

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 0.900s

Which opcode is deprecated but still callable?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
AlexDeveloper @Alexdeveloper

0.900s Time to beat

Second place
SmartContractGuru @SmartContractGuru

1.331s

Third place
John Doe @sleepy-sunbeam

1.714s

Place 4
Victor Anderson @victor-anderson

1.789s

Place 5
Web3WandererAva @Web3Wanderer

1.796s

Place 6
Andria Shines @ChainSage

2.260s

Place 7
Aleksandar Brayanov @chexware

6.420s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 1.367s

Which opcode differentiates EOAs from contracts?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Nishil A @bVcS6U3

1.367s Time to beat

Second place
SmartContractGuru @SmartContractGuru

1.368s

Third place
Harshit Singhal @cnh4gZk

2.222s

Place 4
AlexDeveloper @Alexdeveloper

4.264s

Fastest correct answers rank highest.
View full leaderboard
Blockchain Quiz Medium

Time limit: 10 sec Best 1.582s

Which opcode returns remaining gas?

Practice play. This does not enter the leaderboard.

Press A, B, C, D to answer

Top players

Fastest correct answers

First place
Surya Singu @suryacode

1.582s Time to beat

Second place
Andria Shines @ChainSage

1.912s

Third place
Lydia Ahenkorah Gyamfi @BWN3f48

2.092s

Place 4
Nishil A @bVcS6U3

3.221s

Place 5
Aleksandar Brayanov @chexware

4.590s

Fastest correct answers rank highest.
View full leaderboard