Serhii — Solidity & Full-stack Web3 Engineer, Architect, Team-Lead.

Vetted expert in Blockchain and Cryptography, Smart Contract, Wallet and Web3 Integration, DeFi Ecosystem, DAO/dApps.

Last verified on July, 2025

Senior

Upper-Intermediate English

Core Skills

Bio Summary

• 15+ years of commercial software development experience • Solid knowledge of Solidity, C++, JavaScript, TypeScript; • Deep understanding of blockchain architecture and smart contract logic; • Cosmos, Tron, Avalanche, Binance Smart Chain, Ethereum dApps; • Strong skills in developing NFT smart contracts. Support and payload verification; • NFT Marketplaces (ERC - 721/1155), Crypto Payment Solutions & DeFi Cross Chain Bridges - ERC-20 Tokens, ICO, DEX, Staking, Swapping; • Highly qualified knowledge of Stripe payment system integration to blockchain data; • 10+ years experience working with Python; • 5 years experience working with Node.js; • Strong abilities with Express; • Experience working with Docker, and Kubernetes (K8s); • 3+ years of development experience with React.js. • No scheduled vacations within the next 3 months;

Technical Skills

Programming Languages	C++, JavaScript, Python, R, Solidity, TypeScript
JavaScript Frameworks	Express, Next.js, Node.js, React
UI Frameworks, Libraries, and Browsers	HTML, XML
Databases & Management Systems / ORM	BigChainDB, Cosmos DB, CouchDB, MongoDB, MySQL, PostgreSQL, SQL
Azure Cloud Services	Cosmos DB
Third Party Tools / IDEs / SDK / Services	Asterisk
BlockChain and Decentralized Software	Avalanche, BEP-20, BigChainDB, BSC, DeFi, ERC-1155, ERC-20, ERC-721, ETH (Ethereum blockchain), ICO, IPFS (InterPlanetary File System), NFT, TronChain, Wallets (Integration & Transaction Signing)
Scripting and Command Line Interfaces	Bash, Perl
Virtualization, Containers and Orchestration	Docker, Kubernetes
Deployment, CI/CD & Administration	GitLab CI
Platforms	Odoo
SDK / API and Integrations	Stripe
Other Technical Skills	Payload Verification, Strap

Experience

Founding Software Engineer, DeFi Platform

September 2022- Present

Description: DeFi Platform, built on the Uniswap protocol, specializes in connecting business assets and accounting systems to censorship-resistant distributed systems. Key focus areas include developing cryptographic protocols for custom blockchain systems, creating decentralized applications (DApps) utilizing smart contracts, and facilitating tokenization of digital assets. Platform minimizes transaction fees for users while offering:

NFT integration;
DEX;
Swapping assets;
Farming and Liquidity pools;
DAO / Voting;
Initial DEX Offerings (IDOs);
Launchpools;
Multisend;

The platform has its native token, which is utilized across various functionalities within the ecosystem. In its first year, the platform achieved a trading volume exceeding $1 million.

Responsibilities:

Developing smart contracts;
Building cryptographic protocols and decentralized applications (DApps) based on smart contracts;
Changing NFT protocols and integrating them into the systems;
Developed IDO launches for third-party projects, and users could manage and trade multiple NFTs across accounts;
Creating a decentralized exchange (DEX) with NFT-based authentication;
Design custom tokens and their usage algorithms;
Developing swapping assets, farming, and liquidity pools.

Technologies/Environment: Express.js, CouchDB, Python, React, Next.js, Solidity, Strap, TypeScript, MySQL.

Full-Stack Solidity Engineer, NDA

July 2022- September 2022

Description: NFT marketplace for trading anime-styled images

Transferring NFT marketplace from Binance Smart Chain to Polygon
Developing and deploying new NFT Smart Contracts
Transferring Smart Contracts from ERC-721 token standards to ERC-1155
Developing and fixing features of minting&selling NFTs
Implement features for creating NFT galleries

Technologies/Environment:Nest.js, React, Subgraph, Solidity, Polygon, Binance Smart Chain.

Full-Stack Web and Solidity Engineer, Unvest.io

May 2022 - July 2022

Description: self-service vesting platform with custom release schedules for teams and holders. What makes Unvest different is that the platform generates Liquid Vesting Tokens.

Liquid Vesting Tokens are like coupons that can be redeemed for unlocked tokens at the end of vesting, with the added benefit that they can be transferred, sold, bought, lent, and borrowed against at any time.

Team: 9 people

Responsibilities:

Front-End and Back-End Development
Solidity, Smart Contracts (EVM Compatible: Etherium, Polygon, Avalanche, BNB)

Senior Full Stack Blockchain Dev, Ecosystem for NFT, CXIP Labs.

Aug 2021 - June 2022

Description: Makers of Holograph, a multichain digital asset protocol. Innovative NFT minting for the whole ecosystem. Personal smart contracts, verifiable provenance, advanced royalties, and state-of-the-art security.

Responsibilities:

Developing and connecting NFT to the blockchain using a smart contract.
Supporting and verification of payload in the smart contract logs.
Test backend and consultation on how to add Stripe payment system and blockchain.
On the front end - implementation of portioned uploading of data, signing transactions, verification of payloads, and integration with blockchain for data retrieval.

Technologies/Environment:Blockchain, Ethereum, Solidity, React.js, Typescript, Next.js, Strype

Full-Stack & Solidity Developer, Blockchain Vesting Platform

Feb 2020- August 2021

Description:Self-service vesting platform with custom release schedules for teams and holders. Multi-chain EVM protocol for locking, sending, and trading tokens, offering fully customizable token Vesting and Distribution services.

Responsibilities:

Back-End and Front End, Web3 (UI and off-chain infrastructure)
Wallet Integration, Transaction Multi-sig
building multi-chain dApps (Ethereum, AVAX, Polygon
Smart Contracts (ERC20, BEP20, Polygon, Avax tokens)

Technologies/Environment:Blockchain, Ethereum, Solidity, Avalanche, Binance Smart Chain, React.js, Typescript, Next.js, Strype.

Software Engineer, NDA

Jul 2007 - Feb 2020

Responsibilities:

Blockchain - Ethereum, Solidity, NoSQL (MongoDB), BIGData - BigChainDB, DarfChain.
ERP software development, Linux administration, auth development (saml,oauth2), SOA.
Billing software for ISP, administration of network and Linux servers.
R language - statistical calculations in medicine.

Technologies/Environment: Perl, C++, Bash, Blockchain, MySQL, PostgreSQL, Python, SQL, Asterisk, DB, Java, Python, JavaScript, React.js, HTML, XML.

Education

National University
Specialization – Software engineering
(2006 - 2008) - 2 years
National University
Bachelor in business, computer science
(1993 - 1999) - 6 years

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