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The Metana Blog
Meet our authors →Guides, tutorials & career tips.
Expert-written guides on Full-Stack Development, Web3, AI, Data, and Cybersecurity — built for aspiring engineers and tech professionals ready to level up.
Smart ContractsReentrancy Attack in Smart Contracts
In a traditional transaction, one party sends funds to another in exchange for goods or services. This exchange typically follows a well-defined sequence of steps. However, in the realm of smart contracts,…
Metana EditorialJune 21, 2024Read
SolidityAccess Control in Solidity Smart Contracts
Access control is a crucial aspect of smart contract security, governing who is authorized to perform specific actions within the contract. Just as a bouncer at an exclusive club ensures only permitted guests enter,…
Metana EditorialJune 20, 2024Read
Ethernaut WalkthroughEthernaut Challenge 13 Walkthrough: Gatekeeper One
TL;DR: Ethernaut Challenge 13, Gatekeeper One, tests knowledge of Ethereum transactions and gas mechanics. The GatekeeperOne contract includes three modifiers: gateOne (ensures caller is a contract), gateTwo (requires…
Georgi PlamenovJune 19, 2024Read
BlockchainExploring the Mempool: A Deep Dive
Have you ever sent a cryptocurrency payment and felt like it's taking forever to confirm? You're not alone. Unlike swiping your debit card, crypto transactions don't happen instantaneously. There's a waiting room for…
Metana EditorialJune 18, 2024Read
BlockchainToken Standards: ERC-20, ERC-721, and More
Imagine a world where anything digital can be securely owned and traded. Artwork, in-game items, concert tickets, even your loyalty points – all represented by unique digital tokens stored on a transparent ledger. This…
Metana EditorialJune 17, 2024Read
SolidityTime Units in Solidity: Simplified Guide
Welcome to the fascinating world of smart contracts, where lines of code dictate financial agreements and automate complex processes. But what about time? How do we ensure actions happen at the right moment within a…
Metana EditorialJune 14, 2024Read
Full-StackJavaScript Array Splice() Method
The JavaScript array is a fundamental building block for storing and manipulating collections of data. But what if you need to edit that data – add new elements, remove unwanted ones, or even replace existing items?…
Metana EditorialJune 13, 2024Read
Ethernaut WalkthroughEthernaut Level 12 Walkthrough: Privacy
Ethernaut Level 12 titled " Privacy " challenges the concept of "private" data on the blockchain. In this level, you'll encounter a locked contract, and your objective is to unlock it. The key, however, isn't so private…
Alexis AmoiJune 12, 2024Read
BlockchainTop Languages for dApp Development in 2025: Complete Guide
Decentralized Applications, commonly known as dApps, have revolutionized the way we interact with digital services, providing enhanced security, transparency, and user control. As the backbone of blockchain technology,…
Metana EditorialJune 12, 2024Read
Full-StackDemystifying SSL & Let's Encrypt: Lock in Website Security
The internet is a vast network of information exchange. But have you ever stopped to think about how this exchange happens securely? When you visit a website and enter sensitive information like passwords or credit card…
Metana EditorialJune 11, 2024Read
Ethernaut WalkthroughEthernaut Level 11 Walkthrough: Elevator
Ethernaut challenges , comparable to a Web3-themed hacking Capture The Flag (CTF) competition, offer a dynamic environment for diving into Ethereum and Solidity programming. Each level introduces a distinct smart…
Janos BarnaJune 10, 2024Read
BlockchainOracles and External Data: Boosting Smart Contract Utility
Imagine a program that relies on stock prices to make investment decisions. It checks its internal database, but the information is outdated. The program is stuck, unable to function effectively. This is where oracles…
Metana EditorialJune 9, 2024Read
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