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Hi, I’m Kostan Danil, a backend and full‑stack developer with a passion for building scalable, reliable web applications. I enjoy designing robust APIs, integrating real-time data, and delivering clean, maintainable code. I thrive in collaborative teams and like turning complex ideas into practical software solutions that users love. Outside work, I enjoy learning new technologies, writing tests, and improving development processes. I’m always ready to contribute to open source and help teams ship high-quality software.…Hi, I’m Kostan Danil, a backend and full‑stack developer with a passion for building scalable, reliable web applications. I enjoy designing robust APIs, integrating real-time data, and delivering clean, maintainable code. I thrive in collaborative teams and like turning complex ideas into practical software solutions that users love. Outside work, I enjoy learning new technologies, writing tests, and improving development processes. I’m always ready to contribute to open source and help teams ship high-quality software.

Daniil Kostanda

Back-End Developer, Full Stack Developer, Web Developer, +2

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Hi, I’m Kostan Danil, a backend and full‑stack developer with a passion for building scalable, reliable web applications. I enjoy designing robust APIs, integrating real-time data, and delivering clean, maintainable code. I thrive in collaborative teams and like turning complex ideas into practical software solutions that users love. Outside work, I enjoy learning new technologies, writing tests, and improving development processes. I’m always ready to contribute to open source and help teams ship high-quality software.…Hi, I’m Kostan Danil, a backend and full‑stack developer with a passion for building scalable, reliable web applications. I enjoy designing robust APIs, integrating real-time data, and delivering clean, maintainable code. I thrive in collaborative teams and like turning complex ideas into practical software solutions that users love. Outside work, I enjoy learning new technologies, writing tests, and improving development processes. I’m always ready to contribute to open source and help teams ship high-quality software.

Available to hire

Hi, I’m Kostan Danil, a backend and full‑stack developer with a passion for building scalable, reliable web applications. I enjoy designing robust APIs, integrating real-time data, and delivering clean, maintainable code. I thrive in collaborative teams and like turning complex ideas into practical software solutions that users love.

Outside work, I enjoy learning new technologies, writing tests, and improving development processes. I’m always ready to contribute to open source and help teams ship high-quality software.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Language

English

Fluent

Ukrainian

Advanced

Work Experience

Backend / Full Stack Developer at Yellow Duck Coders

January 20, 2025 - June 20, 2025

Led the development of a Trello-like task management app and a cryptocurrency portfolio tracker. Built high-performance REST APIs using Node.js, NestJS, TypeORM and MySQL; implemented JWT and Google OAuth2 authentication; added Swagger docs, Docker-based deployment, and data validation with class-validator. Implemented nodemailer for email notifications, enforced code quality with ESLint/Prettier, and introduced Redis caching and rate limiting. Consolidated frontend integration with React through reusable components, improving user engagement and reliability.