Oleksandr O — Full-stack Developer

Work Experience

Full-stack Developer, Web Applications Development and Maintenance

Duration: February 2023 — March 2024
Summary: Developing and maintaining web applications with a focus on both front-end and back-end components, ensuring efficient data storage and retrieval, as well as optimizing performance and user experience.
Responsibilities: Developing front-end and back-end components, estimating tasks, code review, refactoring and optimizing applications, implementing various features and functionalities, and updating codebases.
Technologies: PHP, MySQL, Laravel, Git, Bitbucket.

Blockchain Solidity Developer, Blockchain Projects

Duration: August 2021 — January 2023
Summary: Developing blockchain solutions such as smart contracts, payment processor services, wallets, and blockchain explorers, in addition to setting up blockchain networks.
Responsibilities: 

As a main engineer developed more than 10 Solidity Smart Contracts:

• Default ERC-20, ERC-721 Tokens (OpenZeppelin library); 
• ERC-20 with fees, and unique rules of distribution and adding funds to liquidity pools; 
• Staking pools, Time-based reward pools. 

Projected and created Dapps for the smart contracts: 

• Connection with different wallets, like Metamask, TrustWallet, e.g.; 
• Storing user data in databases/blockchain; 
• Executing smart-contract functions (approve, buy tokens, transfer, add liquidity into the pool, withdrawals, e.g);
• Created frontend, backend, API for Dapp using Laravel, Bootstrap 4/5, and paid themes from Themeforest. 

Developed microservices and APIs for collecting and filtering blockchain logs (NodeJS+MongoDB) Created environments for all projects:

• Setting up servers – DigitalOcean, Hetzner Dedicated; 
• Services – Cloudflare, QuickNode, Infura, Block.io, different APIs;
• Blockchain nodes – Ethereum, Ethereum Classic, Binance Smart Network, Bitcoin.

Developed bots for

• Telegram; 
• Discord.

Projects:

• Livenodes Token (LNOT) – ERC-20 (Ethereum Chain) - https://twitter.com/LiveNodes;
• XoXo Smart Contract – BEP-20 (Binance Smart Network) - https://xoxobusd.com/ - Token, Staking Pool, distributing of funds between all of the stakers, funds go from exchange fees on Pancakeswap liquidity pool;
• FriendsTree Smart Contract – paid ladder entry filled with the next two users joining after you, making you earn and rejoin into ladder;
• RewardDao Smart Contract – Vote to Earn project, using snapshot feature, holding token you able to vote for the options provided by token founders – was created to invite people to other projects;
• Web3 Smart Contract – https://web3smc.net sponsor and referral-based system, on-chain distribution of funds between members based on their position in the matrix;
• LegacyStake Token (LST) and Smart Contract - https://legacystake.com/ for staking and Matrix distributing funds – different sponsor-referrals-based pools, and online casinos as use cases.

Technologies: Solidity, NodeJS, PHP, C++, JS, CSS DB: MongoDB, MySQL Env: Hardhat, Truffle, Remix, MERN, LAMP, LEMP, MERN Libraries: Ethers.js, Web3.js, Metamask SDK, WalletConnect DSK Blockchain: Ethereum, Ethereum Classic, BSC, Tron, Bitcoin.

Full-stack Developer, Freelance Full-stack Development

Duration: December 2013 — July 2021
Summary: Executed various freelance projects involving e-commerce solutions, web development platforms, search engines, and systems for product search and sales.
Responsibilities: Developing e-commerce sites, setting up WordPress sites, plugin development, theme creation, developing a rental search engine web application, and creating a system for auto parts search and sales.
Technologies: PHP, HTML & CSS, JavaScript, OpenCart 3, WordPress, Codeigniter 3.