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Maksim
🇵🇱Poland (UTC+01:00)
Created AtUpstaffer since November, 2023

Maksim — Blockchain Software Engineer

Expertise in Blockchain and Cryptography (3.0 yr.), Smart Contract (3.0 yr.).

Last verified on November, 2023

Bio Summary

- Software Engineer with 5 years of experience in building web applications and expertise in blockchain, DeFi, NFT, and tokenization domains. - Proficient in programming languages such as Solidity, Node.js, Python, and Java. - Experienced in back-end development using technologies like Spring, Hibernate, and JDBC. - Skilled in working with blockchain technologies including Ethereum, ERC721, ERC1155, and EIP712. - Familiar with CI/CD tools like Jenkins and containerization platforms like Kubernetes and Docker. - Strong knowledge of database management systems like PostgreSQL, MySQL, and MongoDB. - Well-versed in agile methodologies like Scrum and Kanban, with a solution-oriented approach to project objectives.

Technical Skills

Programming LanguagesJava, Solidity, TypeScript
Java Libraries and ToolsEJB, Java EE, Java Servlets, JDBC, JMS, JSF, JSTL, Lombok, MapStruct, Spring Core, Spring Data
JavaScript Libraries and ToolsEthers.js, Web3.js
Java FrameworksHibernate, Spring, Spring Boot
JavaScript FrameworksNode.js
UI Frameworks, Libraries, and BrowsersPrimefaces
Databases & Management Systems / ORMFlyway, Hibernate, Liquibase, MongoDB, PostgreSQL
Amazon Web ServicesAWS EC2, AWS Security Groups
BlockChain and Decentralized SoftwareAlchemy, EOS, ERC-1155, ERC-20, ERC-721, Ethers.js, ETH (Ethereum blockchain), Hardhat, MetaMask, OpenZeppelin, Polygon, Sushiswap, Wallets (Integration & Transaction Signing)
Version ControlBitBucket, Git
Virtualization, Containers and OrchestrationDocker, Docker Compose
SDK / API and IntegrationsJSP Liferay, Swagger
QA, Test Automation, SecurityJUnit, Mockito
Other Technical SkillsProxies, Slither, Solhint

Work Experience

Software Engineer, Custom Blockchain Platform

Duration: 06.2022 - Till now
Summary:
  • Custom blockchain ecosystem with a compliance-specific for business
  • Truly secure and helpful for reducing the cost of existing tech-stacks
  • With possibility to claim additional rewards if the user has exceeded the deposit limit
Responsibilities: Design REST API; Developing secure Smart Contracts; Testing Smart Contracts; Fuzzy testing; Deploying Smart Contracts on testnet and mainnet; Implementing new Smart Contracts features; Implementation of autoswap from Ethereum to USDC; Database query optimization; FE integration; Scanning the security of Smart Contracts; Writing Hardhat scripts; Using EIP712 for off-chain signature mechanism for gas optimization; Smart Contract gas optimization.
Technologies: Solidity, Ethereum, Hardhat, Ethers, Slither, Solhint, OpenZeppelin, Uniswap, WalletConnect, Metamask, React, Node.js, Rust, Python, Foundry, PostgreSQL, Jira, Confluence

Software Engineer, NFT Marketplace

Duration: 05.2018 - 06.2020
Summary:
  • Smartchain is specifically designed to meet the security and privacy requirements of the financial sector and other industries dealing with sensitive data
  • It is an n+1-tier blockchain where each tier is a separate parachain
  • Three separate para-chains are created for each business, with access rights, that hold digital assets, tokenized securities and smart contracts on a highly scalable and energy efficient infrastructure, allowing businesses to deploy their private blockchain environment, keeping all transactions private within that business' permission tree
  • Another parachain is open to the community and plays an important role in the ecosystem
Responsibilities: Designing RESTful microservices; Load balancing configuration between microservices (optimization taking into account high traffic); Bug fixing in microservices including the ones related to multithreading and memory leaks; Writing smart contracts for deployment and processing of tokens with Solidity; Using ERC721, ERC1155 as base implementations of contracts for working with NFT; Using EIP712 for off-chain signature mechanism for gas optimization as on open sea; Creating a custom token with ERC20; Integration EOS for working with nft; Using Transparent proxy to upgrade smart contracts; Using SushiSwap for integration, connection of the token to the exchanger; Using web3j for implementation of a custom event listener from the blockchain; Using Metamask as authorization provider, integration with backend and frontend; Configure Jenkins jobs; Kafka consumers and producers implementation; Messages processing with Apache Kafka; Utilizing good design practices, code reuse and writing efficient source code; Developing microservices; Functional tests implementation; Investigation and fixing production environments issues; Implementing business features; Configuring Kafka; Database query optimization; Procedures creation in SQL; Implement scripts with Liquibase for DB migration; Managing MongoDB environment from availability, performance and scalability perspectives; Implementing DAO for the MongoDB; Code review of teammates; Writing technical documentation; Interviewing new employees; Maintain systems by monitoring and correcting software defects; Functional tests implementation; Writing unit tests(Mockito), configuring testcontainers; Preparation of technical documentation for newcomers; Active participation in tech and architecture discussions; Communicating with the customer and clarifying solution details; Participation in the discussion of architectural solutions.
Technologies: Java, Spring(Boot, Data, Web, Security, Cloud), Polygon, ERC721, ERC1155, EIP712, ERC20, EOS, Transparent proxy, SushiSwap, Web3j, MetaMask, Solidity, Hibernate, Liquibase, JUnit, Mockito, Infura, Maven, TestContainers, Jenkins, Docker, Docker-Compose, Apache Kafka, MongoDB, PostgreSQL, Swagger, Git, Bitbucket, Lombok, Mapstruct, Jira, Confluence

Software Engineer, NFT Minting Platform

Duration: 06.2020 - 11.2021
Summary: Development of a NFT minting platform for unique characters with the ability to easily customize website, like uploading new backgrounds, locking of NFT claim phases etc.
Responsibilities: Deployment ThirdWeb Smart Contracts; Set up ThirdWeb Smart Contracts; Managing Supabase DB; Integrating Supabase with FE; Integrating web3 libraries with FE; Designing database; Set up Supabase tables and constraints; Uploading FE images to Supabase Storage; Prepare status reports and organize review meetings with management; Identifying tasks and subtasks in modules with the estimating efforts preparing technical design and solution approach documents; Bug fixing; Investigation and use in practice of various architectural solutions; Project documentation.
Technologies: Supabase, React, Ethereum, Solidity, Metamask, Vercel, Thirdweb, Git, GitLab, Jira, Confluence

Software Engineer, Custom Web 3 Game

Duration: 11.2021 - 06.2022
Summary:
  • Web3 game that’s based on car races with different race strategies that allow to slow down competitors
  • Before the start of the match users place a bet on the team they like and wait for a champion
Responsibilities: Design REST API; Developing Smart Contracts; Developing Firebase functions; Providing hardhat scripts; Deploying Smart Contracts to testnet and mainnet; Developing and optimizing DB queries; Integrations with FE; Create database CRUD logic repository layer; Testing Smart Contracts; Create blockchain authentication flow; Scanning the security of Smart Contracts; Smart Contract gas optimization.
Technologies: Firebase, Node.js, Vue.js, Alchemy, Solidity, Jira, Confluence, Docker, Arbitrum, Ethers, Hardhat, Metamask

Education

  • Software Engineering
  • Computer Science

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