Zulfikar Ali

There. My name is Vulfikarelli. And I'm a senior blockchain developer Currently, I'm working for Zulfur Solutions The main business of the company is to educate people on blockchain and web 3 related careers And my role is a Solarity smart contract developer trainer. So, this is, a bit about myself. And, on top of that, I am, having total, 24 years of IT experience, And out of that, my blockchain experience is more than 6 years. So my tech stack is, public blockchain Ethereum, Solidity JavaScript, TypeScript, and, Web 3. Js. And I also have experience in DeFi And on top of that, I have a knowledge about goal language which I have studied in my college or postgraduate diploma time. And I'm well versed with Python coding And so this is a bit about me. And, also, I would like to add that, as for this job requirement, was mentioned that the person or income bank should have crypto trading bot knowledge. So I would like to add on that front that I do have experience of forex trading. I'm a certified forex trader. And that helps me understanding how crypto trading works. And I have also done coding for MQL and MQL 5. For 4x, And, I have, some knowledge about, how crypto trading bot works, which is less similar to our MQL 4 and MQL 5. Coding. So that is a bit about me regarding to this current question.

Okay. The question is, what factors would you consider when selecting a consensus mechanism? For a private blockchain network. Interesting question. So, my experience with private block chain, network is not very much current. I do understand how private blockchain network Look. And, it about it asked about the what factor I'm going to use. So probably, I would like to refer to the type of private blockchain which is being implemented, whether it is a r three quota or whether it's Hyperledger or Hyperledger Peso. And, what kind of network we are creating. If we are creating a network, for example, private network using, let's say, Apple and the DeSou, Then, I would be, lying on security aspect, and, yeah, so security and also, another would be the speed. And, the third factor I would see, How many, blocks, or height of the blocks we are using, before a transaction is considered. A final transaction or a confirmed transaction. So I hope, I've been able to answer this question.

Okay. This question ask about, can you elaborate on designing a liquidity pool smart contract and associated calculations for implementing an automated market maker algorithm. Alright. So when we talk about automated market, maker algorithm, This is kind of algorithm which is creating its own market based on the liquidity pool. So, like, for example, Uniswap. So in the case of Uniswap, the logic is such that you can go and, configure your own native cryptocurrency token and you can make pair with Ethereum or USDT or some other parameter. Cryptocurrency And, you can, let me just be quick once again. Okay. So, but, yeah, basically, when I'm, when I said that We can create our own currency, token and deploy on Uniswap

Okay, this question is how can you optimize guess uses in Solidity functions? That handle array manipulation. So, uh, first of all, uh, we have to be mindful of the thing that, uh, when in the in the case of array, uh, there we should we should be avoiding infinite loop while, uh, counting the array. So our logic should not be a set that, uh, that, uh, that is creating infinite loop. Otherwise, all our guests will be consumed, and it will not be returned back. And, also, we should avoid using, uh, dynamic arrays because it is requires more guests. So, uh, I think we should answer the question because it says, how can you optimize guest usage in certain functions that handle array manipulation? So the first rule of thumb is that we should avoid using dynamic size of array, and we should use fixed array. Second, we need to avoid infinite looping. Uh, it should not clear infinite loop otherwise it will consume all the guesses.

This question reads can you discuss a method to automate withdrawal of funds from a smart contract to multiple beneficiaries and associated challenges. Okay, Suppose we are creating a web 3 application and there we have written a logic that whenever one person is withdrawing fund using that application and at the back end side, it is interacting with the smart contract. So from the front end side, the person will be authorizing withdrawal, uh, transaction using his private key and then the smart it is a smart contract responsibility to make sure that the the multiple addresses or the account or the wallets, uh, which should receive the fund, withdrawal fund, uh, there's no proof upon that front. So, uh, this is one of the things we need to be, uh, of mindful. The smart contract is currently, uh, transferring the, uh, the funds to the correct addresses. And And, also, I believe, uh, the smart contract should be having a reentrancy card, uh, programming done. So there is no reentrancy attack, uh, in the case of withdrawal. Otherwise, the hackers, they can write a smart contract, which can, uh, which can, uh, exploit the level all liabilities if the Adi and Ritzy card is not there or the, uh, the main contract, uh, is not updating its state before transferring the fund. So I believe, uh, redundancy attack is one of the challenges.

Which web 3.js method would you prioritize for efficiently listening to smart contracts event and why? Oh, I think I just forgot that method name. It was web3.eth.event. Uh, or listen event. So I cannot recall it. I have used it to interact, uh, with a smart contract on ether Ethereum blockchain. But at the moment I cannot recall it.

Okay. Here's question that it says, here is a snippet of smart contract in solidity solidity. Mean to emit an event. Explain if there is any mistake in the way the event is defined or emitted. And if so, how it might affect the contract's behaviour? I believe the function has been written correctly. Function make deposit is a public function. It's a payable. It should be payable if it is dealing with receiving or withdrawing the fund. And then it is emit deposit. Event has been correctly called with the 2 parameters message to sender and message to value. I think it has been correctly the event has been correctly defined and emitted. Because I can see address index sender. It has been indexed as well. So indexing is also necessary. So I don't think, uh, if if there is any issues with this code.

The next question says given the solidity function below, explain what the modifier only owner is likely doing before the function execution and identify any potential risk or issues with the implementation assuming owner is a mutable state variable. So the modify the the modifier function only owner it makes sure that sender is the owner. Okay. If it is not the owner then it will it will not go through the required error handler will throw the error and what next only is likely doing before okay I already explained what is likely doing before so it makes sure that the function function is called only by the owner And any potential Okay. Potential, uh, risk is that suppose if you don't use this modifier modifier, which is sure that the sender is the owner, then what will happen? The withdraw function. Any hacker will just call this public function because the public function. If you don't don't put this condition, then any hacker can call this function and withdraw all the fund because we are using message to sender or transfer and balance. So it means all the balance will go. All the balance, uh, of the smart contract will be transferred to the hacker if you don't put this, uh, if you don't use this modifier. So I hope I have answered this question.

Okay. This is very hard. Design a protocol for a cryptographically secure decentralized porting system using smart contracts that minimizes the risk of voter fraud and manipulation. So, basically we are going to write a smart contract in Solidity and in order to minimize the risk of water fraud. So what should happen that in this smart contract, uh, let's say, uh, we are going to, uh, create a voting for selecting the proposals. Let's say there are multiple proposals configured in the smart contract and then there will be, uh, a number of voters who should be made eligible, uh, by the owner or the admin. So when we are when we are configuring the smart contract in the constructor, we should make sure that who is going to be the owner. Whether the person who is deploying the smart contract, he's going to be the owner or, um, there is other way to identify the owner. So there's one way the person who is deploying the smart contract, he can be the owner, or in the constructor, you can mention different addresses or the one address, uh, uh, who can be, uh, the owner. And from there, once the contract has been deployed, then the owner, the designated owner in the system, either one owner or multiple owners, they should have this, uh, right to create voters. So they will be a pipe listing the voters. So we can write function where they can create voter, and, uh, in a sense, they will be, uh, a a function which will be taking address, uh, of different voters and putting in a array or a mapping. You can use mapping also. So it will make sure that so and so address is eligible to vote. And then, uh, another thing we can use, a delegate function. We can create a delegate function. So there, the voter, if he doesn't want to vote, he can interact with a smart contract, and there should be a function like, uh, delegate, uh, voting rights, something. So he should be able to delegate his right to someone else. So in this fashion, you know, we can minimize the fraud that, you know, uh, other person cannot uh, work, um, uh, without, uh, without the permission, uh, of the original voter, uh, other can cannot work on the behalf of that particular voter until unless, uh, the original voter has, uh, authorized someone else, uh, or delegated someone else to work on his behalf. So I believe if these are the mechanism in place, uh, we can create a cryptographically secure decentralized voting system. Yeah. So I think this is my answer.

Okay. This is what DevOps practices would you recommend for continuous integration and deployment of blockchain applications? So continuous DevOps, uh, I would say that, uh, nowadays we are using GitHub. So the moment we upload any updated smart contract, automatically the programs are there and, uh, automatically, it is tested, uh, on the GitHub itself. So there is one thing I would, uh, recommend that not only you do a local testing, you know, locally also before we upload any smart contract to the blockchain, we do some kind of testing either in truffle, hard head, brownie, or foundry. We use these testing mechanism, but also there is a extra layer on GitHub, uh, which test, uh, the smart contract. So automated automated local testing and, uh, see, uh, CICD testing on GitHub are the mechanism So that your blockchain is Continuously integrated with the main application

Okay. This question asked me design a strategy for onboarding a user in a Dapp while maintaining a balance between user experience and stringent security practices. So I do have experience of working in, uh, d f development projects, and we used to have a fruitful discussion with the UI UX designer. So, uh, it is also true that, uh, be it being a web 3 application, it is not that straightforward. And in, generally, web 2 applications, once you initially, uh, once you enter your data, like your name, email ID, uh, password, and some information, your user ID is created. But since it is d f and chances are that we might be using some kind of web three authentication system. So, um, behind, uh, under the hood, it works a bit differently because it creates a kind of unique key once you enter the data. And then based on the unique key, it creates a wallet for you on the blockchain. So, uh, what happens, uh, if you see on the mobile in the UI UX, then there is a first of all, there is some lag, uh, immediately, uh, when you, uh, when you enter the your data, you create a profile. Immediately, your wallet may not be ready. So first of all, that lag will be there, and you also need to display to the user that his his wallet has been created and user will be eager to, uh, access his wallet. And then user might be having some confusion that how to access his wallet. Suppose if you have attached your web 2 application to a text, So it might not be that quick, and, um, maybe user would like to, uh, ask for the wallet address and his private key. And if your application, um, logic doesn't allow, uh, the user to access his private key, then there may be some doubt on user on user's mind that why I'm not being given my private key. So, uh, we need to make a balance here. When initially the onboarding is happening, the user should be a satisfied user in the end of onboarding. At the end of onboarding, the user should not be confused that what has happened to his profile, why he is not able to immediately, uh, do, uh, transaction, or why, uh, he is not able to see his balance. Sometime, you would not like to, um, populate his wallet immediately. Suppose he has deposited deposited some fund, and, uh, you as a platform creator or owner, you would like to stop or wait for some time before you, uh, populate his actual wallet in the blockchain. So the user may be anxious that I had deposited $100 but I cannot see the token right now because you are you want to send a transition in batches. So sometime in, uh, you know, it may take some time. Maybe you send your badge after 30 minutes, every 30 minutes or every 60 minutes. So user may not be happy with this, uh, delay or late, then you need to educate your user and, uh, you know, take him into confidence that it will be, uh, available or visible after 30 minutes or 60 minutes, so and so. So, I believe that will be my answer.