Oleh

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Oleh Hurmanchuk
[відкрити контакти](див. вище в блоці «контактна інформація») Full Stack Developer
LinkedIn I am a backend-oriented developer with 3 years of experience in fullstack
development of web applications. I have developed SaaS projects and platforms in
GitHub
the FinTech, DeFiTech and Web3 domains.
[відкрити контакти](див. вище в блоці «контактна інформація») On the backend side, I developed new functionality for processing data from tens of
Vinnytsia / remote / hybrid different sources with different standards and combined all that in developer friendly
API. I worked on caching system that allowed to work with the freshest data while
Proficiencies also lowering our requests to external APIs by 50%. I am currently actively learning
Go while also playing around with C-like languages to improve my knowledge of how
Programming languages: computers work and how to write optimal, fast code.
On the frontend, I worked on applications of varying complexity: some were simple
Javascript, Typescript
sites with barely any client functionality, while the others were client heavy
Golang applications that had to do almost everything in the browser without communicating
Front-End Development: with backend for the sake of security and anonimity of the users. I worked on a
Next.js desktop port of mobile application for secure text and video communication with
React, Vue, Svelte integrated simple crypto wallet functionality using Electron.js.
HTML5, CSS3, Sass (SCSS),
TailwindCSS
Experience
Electron.js April 2024 - Present
Back-End Development: Technologies: JavaScript, Typescript, React, Node.js, Express.js, Nest.js, Next.js,
Node.js, Express, Nest.js Electron, Ethers.js
Database and API: Full Stack Developer at Chainza
Built backend infrastructure for a decentralized payment solution in collaboration
REST API
with the team, leveraging modern Web3 technologies such as Moralis, QuickNode,
SQL, PostgreSQL, MySQL and other common blockchain resources
Version Control and Tools: Designed and implemented backend services for a multichain wallet (20+ chains),
including token balance indexing, allowance tracking, USD price aggregation from
Git/GitHub
external APIs, token list synchronization, and real-time gas price estimation
VS Code, NeoVim Developed a mobile cryptocurrency wallet with built-in crypto swaps, purchasing,
ClaudeAI and a unique gifting feature, implementing core wallet and transaction flows
Working together with another team, ported and developed a desktop version of a
mobile application, implementing secure encrypted messaging and calling
functionality alongside integrated cryptocurrency wallet

January 2024 - March 2024
Technologies: JavaScript, React, Typescript, HTML, CSS, Node JS.
Full Stack Developer at DevMaxUp
Contributed to the user-friendly and responsive UI development of an admin panel
for a finance management application
Worked on the UI part for a video creator application, enhancing the user experience
with intuitive workflows and modern design practices
Refactored the authentication flow of the application to improve security,
implementing robust session management, token handling, and protection against
common vulnerabilities such as XSS and CSRF
Languages Projects
English - Upper-Intermediate (B2) ExtraSafe
Ukrainian - Native speaker Self-custodial secure messenger with integrated crypto wallet.
German - A2 On this project I worked both on the backend and frontend of mobile
application’s crypto wallet. I also ported wallet part to the desktop.
Tech-stack: Typescript, React, Electron.js, Node.js, Express.js, TailwindCSS
Achivements Site
Antelope Memento API
Implemented caching system that
A lightweight history service for Antelope (ex-EOSIO) blockchains.
shortened requests to external APIs
I improved reliability of the API, fixed bugs and added logging for easier future
by 50%
analysis of the problems. Technologies: Typescript, Express.js, Socket.IO
Github
PayDeFi: crypto payment solution
Decentralized payment solution that would allow its users to pay for mundane
things like clothes, games and subscriptions using cryptocurrencies. I was
responsible for backend development and used Typescript, Nest.js and
PostgreSQL on this project.