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title: Frontend questionnaire

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Recommended study materials:
1. Book https://landing.coingecko.com/how-to-defi/
2. The general structure of blockchain and cryptography:
- https://www.youtube.com/watch?v=bBC-nXj3Ng4&t
- https://www.youtube.com/watch?v=S9JGmA5_unY
3. Download different crypto wallets. Test the wallets. Explain about their specific characteristics. What features do they support? 
4. If you have difficulties with "fields / groups", then you can refresh your knowledge: https://www.youtube.com/watch?v=IP7nW_hKB7I&list=PLi01XoE8jYoi3SgnnGorR_XOW3IcK-TP6
5. Private / public keys / addresses / hd path, can be seen in practice here (available with source code)
https://iancoleman.io/bip39/#english
6. Ethereum:
- https://github.com/ethereumbook/ethereumbook
- https://cryptozombies.io
- https://hardhat.org/tutorial
- https://tenderly.co
- https://eips.ethereum.org/EIPS/eip-20
- https://eips.ethereum.org/EIPS/eip-712
- https://eips.ethereum.org/EIPS/eip-2612
- https://etherscan.io
- https://etherscan.io/address/0x1111111254fb6c44bac0bed2854e76f90643097d#code
- https://etherscan.io/address/0x111111111117dc0aa78b770fa6a738034120c302#code
- http://docs.1inch.io/
7. Сheck out the first 4 chapters of the book to learn more about ECDSA 
https://www.amazon.com/Programming-Bitcoin-Learn-Program-Scratch/dp/1492031496


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General on Ethereum & blockcahain:
 1. What is blockchain in simple terms?
 2. What are the three main technologies in cryptography? 
 3. What is a cryptographic hash function? What are the basic attributes of a hash function?
 4. What is an address in blockchain and what is a private key?
 5. How is an address related to a private key? What is a transaction signature?
 6. What consensus types do you know?
 7. What is a transaction in bitcoin? What does a transaction consist of?
 8. What is a transaction in ethereum? What does a transaction consist of? 
 9. What is a block in blockchain? What does a block consist of? What do the elements of a block mean?  
 10. What is HdWallet? 
 11. What do fields mean and how are they related to each other? https://iancoleman.io/bip39/ 
 12. What is gas, what is gasPrice? How the transaction cost is calculated?
 13. Why do you need gas limit per transaction and per block? What problems does it prevent?
 14. What is crypto gas war?
 15.  How do you technically cancel a transaction and accelerate a transaction?

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Communication between node and wallet via JSON RPC: 
1. What methods are used for it? What information can be received using each of them? 
 - eth_getBalance
 - eth_call
 - eth_estimateGas
2. What are these methods used for? How do these methods differ from each other? 
 - eth_sendTransaction
 - eth_sendRawTransaction
3. What is an ERC-20 token? What are the functions of an ERC-20 token and how do the functions work? 
4. What is EIP-712? What problem does it solve? How does it work?
5. What is EIP 1559? What problem does it solve? How does it work? 
6. What problem does EIP-2612 Permit solve? How does it work? What does it consist of? How to cancel permit? Who pays for the permit? 
8. How to get token balance? How to check if there is a allowance? 
9. What are FOT tokens? 
10. How to recognize tokens with a fee via the smart code?
Using this token as an example, what part of the code is responsible for taking the fee? https://etherscan.io/token/0xa68dd8cb83097765263adad881af6eed479c4a33

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Product 
1. What is a decentralized exchange? What decentralized exchanges do you know? 
2. Give a couple of examples of how decentralized exchanges work? 
3. What is price slippage?
4. What are limit orders in blockchain (1inch Limit Order Protocol). What are the features? 
5. Gnosis Safe. How does it work? Why do I need it? What is multisig?
6. What networks does 1inch support? Tell me the features of each of them? 

