Serhii Markov
Full Stack Web & Mobile Developer
With 4+ years of experience in full stack web and mobile development, I create modern, user-centric apps that merge technology with design. From web platforms to Telegram Mini Apps and React Native experiences — I build products that work beautifully and perform flawlessly.
About Me
Get to know more about my background, skills, and passion for development
I'm a Full Stack Web & Mobile Developer specializing in modern web apps, Telegram Mini Apps, and blockchain-integrated platforms. I build scalable, user-focused solutions using React, Next.js, TypeScript, and Node.js — seamlessly connecting web experiences with mobile technologies like React Native and Expo. My recent work includes integrating Telegram SDK and TON Connect for real-time interaction, payments, and community-driven ecosystems. Passionate about clean architecture, teamwork, and creating products that truly engage users.
Soft Skills
Education
Lawyer (Qualification in Criminal Police)
Kharkiv National University of Internal Affairs
2004–2008
Additional Education
- Full Stack Developer — IT School GoIT (July 2020 – July 2021, Ukraine)
Skills & Technologies
Technologies and tools I work with to bring ideas to life
Frontend
Mobile Development
Backend & Integration
Testing & Quality
Tools & Workflow
Professional Experience
Full Stack Web & Mobile Developer
2021 – PresentCyberLeaf
Developing modern web and mobile applications with focus on performance, scalability, and UI/UX quality. Responsible for implementing new features, maintaining production apps, and improving front-end architecture using React, Next.js, and TypeScript. Collaborated within Agile teams, integrating Firebase, REST APIs, and PWA technologies.
- Built and maintained several production-level web and mobile apps using React, Next.js, and React Native
- Integrated Firebase, WebSocket, and REST API services for real-time communication and data synchronization
- Contributed to the development of internal tools improving project delivery efficiency
- Optimized applications for SEO and performance, achieving Lighthouse scores of 90+
Full Stack Developer / Consultant
Dec 2024 – PresentFreelance Projects
Working with international and local clients to deliver custom full stack web and mobile solutions. Focused on Telegram Mini Apps, PWA development, SEO optimization, and technical debugging for existing codebases.
- Developed and launched the SUP.port PWA — a bilingual booking platform for SUP board rentals in Cherkasy
- Created GrinG — a Telegram Mini App integrating TON blockchain payments, rewards, and community investment features
- Built Asparagus Store — a localized e-commerce platform with responsive design, recipes, and Google Maps integration
- Provided debugging, refactoring, and SEO optimization for multiple client projects
- Contributed to a humanitarian Expo-based app aiding bomb disposal specialists in identifying and neutralizing explosive devices
Featured Projects
Some of my recent work that showcases my skills and expertise
GrinG Telegram Mini App
An innovative Telegram Mini App that enables users to invest in real businesses, earn points, and participate in community-driven decisions using TON blockchain integration. Features include TON payments, referral system, rewards, and multilingual support.
SUP.port — SUP Board Rental Platform
A Progressive Web App (PWA) for online SUP board and tour booking in Cherkasy. Fully localized (uk/en), optimized for SEO, and designed with Apple-inspired UI animations. Integrates Telegram notifications and Firebase Firestore.
Asparagus Store — Online Shop
An e-commerce platform for selling asparagus with product catalog, localized content, and recipe library. Includes responsive drawer navigation, SEO optimization, contact forms with EmailJS, and Google Maps integration.
OSBB Management System
A Progressive Web App (PWA) designed to manage residential buildings. It helps track energy consumption, manage finances, send interactive notifications, and improve community communication.
Corporate Chat Application
A real-time corporate chat solution with WebSocket and Mattermost API integration. Supports team communication, file sharing, and continuous data exchange between client and server.
Realtors Platform
Cross-platform mobile app for real estate search, rent, and sales. Features include advanced filters, realtor profiles, and property management tools.
OS.community Mobile App
A mobile app built for private communities — enabling chats, events, news, and access control. Includes Firebase Authentication, Firestore, and Realtime Database for dynamic data handling.
Interested in working together? Let's discuss your project!
Start a ProjectWhat Clients Say
Testimonials from satisfied clients and collaborators
"Serhii delivered an exceptional React application that exceeded our expectations. His attention to detail and technical expertise made the development process smooth and efficient."
Sarah Johnson
Product Manager
TechCorp
"Working with Serhii was a game-changer for our project. He transformed our ideas into a beautiful, functional web application that our users love. Highly recommended!"
Michael Chen
Startup Founder
InnovateLab
"Serhii's technical skills and collaborative approach made our design-to-development handoff seamless. The final product was pixel-perfect and performant."
Emily Rodriguez
Design Director
CreativeStudio
Ready to work together? Let's create something amazing!
Start Your ProjectGet In Touch
Ready to start your next project? Let's discuss how I can help bring your ideas to life
Let's Connect
I'm always interested in new opportunities and exciting projects. Whether you have a question, want to collaborate, or just want to say hi, feel free to reach out!
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