Serhii K.
Senior Software Engineer
Experience
Sep 2021 - Oct 2024
3 years 2 monthsUnited States
Senior Software Engineer
Kilwar LLC
- Built a robust logistics platform supporting multi-party delivery coordination between shippers, drivers, and end-users.
- Developed event-driven architecture using Nest.js and RabbitMQ for seamless updates and communication.
- Designed the database schema with PostgreSQL using DrizzleORM, handling millions of shipment records and tracking logs.
- Built modern, component-based UIs using React and Tailwind CSS, including dynamic forms with React Hook Form and server-side state sync using React Query.
- Integrated end-to-end tests using Playwright and unit tests via Jest, achieving nearly 90% test coverage.
- Scaled platform to handle 5,000+ monthly users across web and mobile.
Jul 2020 - Aug 2022
2 years 2 monthsUnited States
Software Engineer
Eatcheap Agency
- Developed a restaurant discovery and food delivery marketplace targeting the U.S. market.
- Architected both frontend (React and Tailwind CSS) and backend (Nest.js, PostgreSQL and Redis).
- Implemented Pub/Sub architecture with RabbitMQ for order dispatch and real-time notification handling.
- Used CQRS patterns to separate read/write models in a performant system design.
- Created admin dashboards for restaurants to manage inventory, menus, and daily promotions.
Mar 2018 - Mar 2020
2 years 1 monthGermany
Software Engineer
NERDZZ Digitalagentur GmbH
- Architected and developed Trado, a secure e-commerce platform available as both iOS and web app.
- Built OTP-based authentication, multi-role logic, and encrypted user flows.
- Integrated Cloudinary for image uploads and optimized storage with AWS S3.
- Developed real-time features using Firebase and socket communication.
- Codebase and project insights available upon request.
Jun 2016 - Mar 2018
1 year 10 monthsGreece
Software Engineer (Intern)
NUS Solutions Inc
- Developed and maintained scalable web applications using React.js, Next.js, and TypeScript, ensuring high performance and seamless user experience.
- Designed and implemented RESTful APIs and GraphQL endpoints to optimize data fetching and improve application efficiency.
- Integrated Redux for state management, enhancing application responsiveness and reducing load times.
- Spearheaded UI/UX improvements by implementing Tailwind CSS, Material UI, and custom component libraries, leading to a 30% increase in user engagement.
- Optimized frontend performance by implementing lazy loading, code splitting, and caching strategies.
- Collaborated closely with backend developers to integrate APIs, debug issues, and ensure smooth communication between frontend and backend.
- Led the migration of a legacy application to modern web technologies, improving maintainability and scalability.
- Implemented CI/CD pipelines using GitHub Actions and GitLab CI to automate deployments and testing, reducing manual effort by 15%.
Summary
Experienced Full-Stack Developer with over 6 years of hands-on experience in building scalable backend systems using Node.js, Nest.js, and PostgreSQL, combined with solid frontend expertise in React, TypeScript, and Tailwind CSS. Proven track record in designing and implementing Event Sourcing, CQRS, and Pub/Sub architectures using tools like RabbitMQ and Redis. Adept at writing clean, maintainable code with strong test coverage using Jest, Supertest, and Mocha. Passionate about working in close-knit teams where ownership, communication, and code quality are key.
- Architecture
- Integration Strategy
- 0 - 1 Product Development
- API Design and Development
- UI/UX Design and Development
- Software Development
- Global/Local People Management (Onshore/Offshore)
- Product/Project Collaboration
- Process Structuration and Optimization
- Executive Leadership
- Continuous Improvements
- Professional DevOps Services
Languages
Greek
NativeEnglish
AdvancedEducation
Apr 2010 - Sep 2014
University of Peloponnese
Bachelor's degree in Computer Science and Mathematics · Computer Science and Mathematics · Greece
Certifications & licenses
Agile Development Certification
Institution of Peloponnese
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