ArtofBlockchain

Community Feed

Difficulty - Medium

Total Plays - 1,594

Allowed Time - 10 sec

Best time - 0.784

What determines the base slot of a mapping?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
The base slot of a mapping is derived using keccak256(key . slot). This hashing ensures unique storage locations per key without collisions.

Leaderboard
Aditi Rao
@aditi-rao • Dec 28, 2025

Dec 28, 2025
478

Clean code, but still rejected — what do juniors miss in take-home assignments?

I’m a junior developer and I keep running into the same problem. My take-home assignments usually work, the code is clean, but I still get rejected — often without any...

Like 3 Replies 4
Difficulty - Medium

Total Plays - 17

Allowed Time - 10 sec

Best time - 3.845

Which function type cannot access msg.sender?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
pure functions cannot read blockchain context such as msg.sender or block.timestamp. They are restricted to computation based solely on input parameters and local variables

Leaderboard
Shubhada Pande
@ShubhadaJP • Jul 13, 2026

Jul 13, 2026
1.8K

Debugging, Tooling & Production Engineering

This sub-cluster exists because most Web3 engineering content stops at “tests passing.” In real teams, the hardest problems appear when: contracts behave differently on testnet vs mainnetlogs look correct but...

Like 3 Replies 1
Jatin R
@5EB8S0F • Jun 23, 2026

Jun 23, 2026
3.3K

Blockchain QA for Software Testers: Do You Need Solidity, Foundry Tests, or Bug Reports?

Is blockchain QA closer to normal test engineering, smart contract testing, or security-style bug finding? Also, for US remote roles, what do hiring managers actually trust as proof — test...

Like 3 Replies 10
Difficulty - Medium

Total Plays - 14

Allowed Time - 10 sec

Best time - 1.493

Why are fallback functions dangerous?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
Fallback functions run automatically when unknown calls or plain ETH are sent. If they contain external calls or heavy logic, attackers can trigger recursion or re-entrancy. They must be kept minimal and safe.

Leaderboard
John Mathew
@BABXSUw • May 24, 2026

May 24, 2026
1.6K

Is a compliance certification enough for a global Web3 legal career, or do I need a specialized LLM too?

I’m trying to move from international law into global Web3 compliance and digital asset regulation, but I’m confused about the credential path. For someone targeting crypto AML analyst jobs, VASP...

Like 3 Replies 4
Fady Efat
@hACjMzw • Dec 5, 2025

Dec 5, 2025
503

Guidance on Next Steps for Web3 Development Career

Hi everyone, I’ve developed 2 projects on the Spoilya network using Flutter: A one-time voting app.Clicker Bee mobile game with NFTs.and 1 using react with helping AI ,Crypto Tracker I’m...

Like 3 Replies 6
Difficulty - Medium

Total Plays - 9

Allowed Time - 10 sec

Best time - 7.363 sec

What makes memory expansion expensive?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
Memory follows a quadratic cost function, meaning costs rise rapidly as the memory footprint grows. Careless array allocations can suddenly inflate execution cost. This is a frequent root cause of gas blowups in audits.

Leaderboard
Difficulty - Medium

Total Plays - 10

Allowed Time - 10 sec

Best time - 2.358

Why is PUSH0 useful in gas optimization?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
PUSH0 provides a zero literal without consuming calldata or memory. This reduces bytecode size and simplifies stack management. It's extremely helpful in tight loops and assembly-heavy contracts.

Leaderboard
Difficulty - Medium

Total Plays - 8

Allowed Time - 10 sec

Best time - 2.492

What does REVERT preserve that INVALID does not?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
REVERT allows returning structured revert data back to the caller, which improves debugging and interface guarantees. INVALID terminates execution with no return payload. This distinction is crucial for protocols relying on bubble-up error messaging.

Leaderboard
Difficulty - Medium

Total Plays - 7

Allowed Time - 10 sec

Best time - 3.912

Which op is used for external code size?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
EXTCODESIZE checks if the target has code deployed. It helps detect contracts vs EOAs in validation logic

Leaderboard
Difficulty - Medium

Total Plays - 8

Allowed Time - 10 sec

Best time - 10

Why are multi-step writes risky?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
Multi-step operations can leave the contract in a partially updated state if execution halts. Attackers exploit these interim states to bypass checks.

Leaderboard
Difficulty - Medium

Total Plays - 6

Allowed Time - 10 sec

Best time - 5.375

Why is SELFDESTRUCT dangerous in proxies?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
If the implementation contract is self-destructed, proxies break permanently or redirect unexpectedly. This creates bricked contracts and undefined behavior

Leaderboard
Difficulty - Medium

Total Plays - 9

Allowed Time - 10 sec

Best time - 10

What does RETURNDATASIZE prevent?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
RETURNDATASIZE ensures the caller knows exactly how many bytes were returned. It prevents incorrect assumptions and truncation bugs during low-level calls.

Leaderboard
Shubhada Pande
@ShubhadaJP • Jul 9, 2026

Jul 9, 2026
2.5K

Proof-Based Hiring in Web3: A Founder’s Guide to Evaluating GitHub, Tests, Smart Contracts, and Audit Claims

Updated for 2026 Web3 hiring signals: this guide focuses on how founders, recruiters, and hiring managers can evaluate blockchain candidates through visible proof before relying on interviews alone. While hiring, most founders review code thoroughly, as the wrong hire can cost massively. In the Web3...

Like 3 Replies 1
Difficulty - Medium

Total Plays - 8

Allowed Time - 10 sec

Best time - 3.010

5. Why is delegatecall risky?

Tip: Click "Play" to reveal options and start playing.

#A

#B

#C

#D

Explanation:
delegatecall executes callee code in the caller’s storage context, leading to storage collisions and privilege escalation. This is a key attack vector in proxy contracts.

Leaderboard
Arif
@ofh3VYy • Nov 25, 2025

Nov 25, 2025
386

🚀 I Want to Become a StarkNet/Cairo Auditor — Here’s My Starting Point & I’d Love a Roadmap

I’m transitioning my focus toward StarkNet and Cairo security auditing and would appreciate guidance from anyone experienced in the ecosystem. What I know so far: • Solidity development • Hardhat,...

Like 3 Replies 4
Ayush Verma
@NawtFound404 • Nov 20, 2025

Nov 20, 2025
499

Silent Fails in Smart-Contract Access Control: What Teams Miss Until It’s Too Late

While practicing with Slither/Mythril and extracting CFGs from Solidity contracts, I keep noticing a pattern:Teams don’t get hacked because of complex bugs.They get hacked because of small access-control oversights. Examples...

Like 3 Replies 3
Akemi R
@snappy-bullet • Jun 29, 2026

Jun 29, 2026
550

Got removed from my first blockchain job — now scared to ask for help again

This is my second blockchain developer job, and I am still not able to come out of that bad experience. They didn't want to just because I asked too many...

Like 3 Replies 6