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Ilya SlyusarchukIS

Ilya Slyusarchuk

Supermalter

Senior Full-Stack Developer | NextJS, Java, Python

EUR 270/Tag
5 Projekte
Alicante, ES
3-7 Jahre

Durchschnittliche Reaktionszeit: 1h

Über Ilya

I’m a freelance Senior Full-Stack Developer helping companies build, maintain, and improve modern web applications, SaaS products, dashboards, APIs, automation tools, and Web3-enabled user experiences.

Since becoming self-employed in 2020, I’ve worked across multiple client projects, from startup products and Telegram mini-apps to enterprise applications in the financial sector.

My main experience covers full-stack development with React, Next.js, Node.js, TypeScript, JavaScript, Java, Python, REST APIs, GraphQL, databases, authentication, cloud services, CI/CD workflows, and production application maintenance.

Since 2024, I’ve also incorporated AI-assisted and agentic coding tools into my development workflow to improve productivity, accelerate research and implementation, support code review, and deliver high-quality output more efficiently. I use these tools as part of a structured engineering process, while keeping architecture, code quality, security, testing, and final technical decisions under my own control.

My Web3 experience is focused on integrating blockchain functionality into products rather than protocol or smart contract development. This includes wallet connections, blockchain transaction flows, smart contract interactions, token-based access, dApp interfaces, and connecting traditional web applications with EVM-compatible networks.

I can help with:

• Full-stack web application development
• SaaS MVPs and product dashboards
• React / Next.js frontend development
• Node.js / TypeScript backend development
• Java and Python application development
• API design and third-party integrations
• Authentication, user roles, and admin panels
• Telegram bots and Telegram mini-apps
• Web3 wallet and blockchain integrations
• Enterprise application maintenance and feature development
• Cloud, CI/CD, Docker, deployment, and production debugging

Open to freelance projects, long-term collaborations, and senior technical consulting.
  • Spanisch

    Muttersprachlich oder zweisprachig

  • Englisch

    Verhandlungssicher

  • Russisch

    Muttersprachlich oder zweisprachig

  • Portugiesisch

    Grundkenntnisse

Nur remote
Führt Projekte hauptsächlich remote aus

Projekt- und Berufserfahrung

  • Freelance
    Freelance Full-Stack Developer
    Januar 2020 - Heute (6 Jahre und 5 Monate)
    Providing full-stack development services for startups, founders, and small businesses, helping build, improve, and maintain web applications, dashboards, APIs, automation features, and Web3-enabled product experiences.

    Worked across multiple freelance projects, contributing to product development, implementation, integrations, bug fixing, deployment support, documentation, and long-term technical improvements.

    Main areas of work:

    • Full-stack application development with React, Next.js, Node.js, TypeScript, JavaScript, REST APIs, databases, authentication flows, dashboards, and admin interfaces.
    • Frontend development focused on responsive layouts, reusable components, mobile-friendly interfaces, clear user flows, and product-oriented UI improvements.
    • Backend development involving API endpoints, business logic, database models, user management, role-based access, integrations, and server-side application features.
    • Third-party integrations with external APIs, payment flows, storage services, notification systems, automation tools, and other product-specific services.
    • Web3 integrations for full-stack products, including wallet connections, blockchain transaction flows, smart contract interactions, token-based access, and dApp-style user experiences.
    • Deployment and delivery support, including production preparation, environment configuration, version control workflows, cloud/VPS deployment assistance, and post-release debugging.
    • Collaboration with clients, founders, designers, and existing development teams using Git, GitHub, task management tools, documentation, progress reporting, and structured handoff materials.
    • Testing, debugging, refactoring, performance improvements, and maintainability work to make applications more stable, reliable, and easier to evolve.
    Full-Stack Development React.js Next.js Typescript Node.js
  • Minsait
    Senior Full-Stack Consultant
    März 2024 - Heute (2 Jahre und 3 Monate)
    • • Maintain and develop internal banking applications using Java, Python, Spring, Flask, JAX-RS, and related backend technologies.
    • • Build and improve full-stack application features across frontend, backend, API, and integration layers.
    • • Develop new features, fix bugs, refactor existing code, and improve the reliability and maintainability of production applications.
    • • Work with Google Cloud Platform, Jenkins, GitHub, and CI/CD workflows to support development, testing, and delivery processes.
    • • Collaborate with development teams using Jira, Git-based workflows, code reviews, issue tracking, documentation, and structured delivery processes.
    • • Analyze business and technical requirements, investigate existing systems, and implement changes in applications used within a banking environment.
    • • Work in a financial-sector context where maintainability, security, traceability, reliability, and process discipline are critical.
    Python Java Spring flask Google Cloud Platform (GCP)
  • Matera
    Lead Software Developer
    März 2024 - April 2025 (1 Jahr und 1 Monat)
    Worked as a contractor and lead full-stack developer, owning the architecture and development of two high-scale applications: Matera, with 50K+ users, and TapBidz, a Telegram mini-app with 200K+ users.
    • • Architected and developed production apps using React, Next.js, TypeScript, and responsive frontend patterns for performant web and mobile-friendly experiences.
    • • Designed and implemented serverless backend architecture on AWS using AppSync, DynamoDB, Lambda functions, and real-time synchronization.
    • • Built authentication and authorization flows with AWS Cognito, including user sessions, protected routes, access control, and privacy-oriented data handling.
    • • Engineered real-time auction functionality for TapBidz using WebSocket communication, enabling live bidding, price updates, synchronized auction states, and concurrent user interactions.
    • • Developed gamification features such as daily tasks, rewards, referrals, progression flows, and retention-oriented mechanics.
    • • Implemented wallet integration flows for crypto rewards, allowing users to connect blockchain addresses and receive rewards.
    • • Created frontend state management with Recoil across auctions, balances, rewards, authentication, user progress, and real-time UI updates.
    • • Built backend logic, API integrations, database structures, and event-driven flows to support scalable product behavior.
    • • Established CI/CD pipelines using CircleCI and AWS deployment workflows for consistent releases and faster delivery.
    • • Improved performance by optimizing API calls, caching, frontend rendering, real-time updates, and backend communication.
    • • Used Git workflows, task management, documentation, testing, debugging, and structured release processes.
    • • Led technical execution while collaborating with stakeholders to define priorities, report progress, and turn requirements into production-ready features.
    Next.js AWS Web3 MongoDB Typescript

Bewertungen

5.0

Von 3 Bewertungen

A

Alexander

Tech Lead - INDRA SOLUCIONES TECNOLOGIAS DE LA INFORMACION SL

Mehrmonatiges Projekt

-

Bewertet am 15.12.2025

Profesional, comprometido con el equipo, muy responsable, técnicamente totalmente autónomo
FranF

Fran

SoyFranGarcia

Bewertet am 20.8.2023

De nuevo Llya implementó soluciones rápidas y efectivas para algunas necesidades de php. Volveré a trabajar con él sin duda.

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Ausbildung und Abschlüsse

  • Engineer's degree, Computer Science
    Universitat d'Alacant
    2023
    - Excelled as a distinguished member of a top-tier Computer Science program, exclusively taught in English. - Maintained an impressive academic record, achieving an average grade of 8.7 out of 10 and demonstrating exceptional performance and dedication to the field. - Earned multiple honorific mentions in recognition of consistent academic excellence.
  • Engineer's degree, Computer Science
    Gdansk University of Technology
    2022
    - Mainly specialized in Machine Learning and Python development. - Maintained an impressive academic record, achieving an average grade of 9.2 out of 10.

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