Serhii Korol
Senior Software Engineer
Experience
Senior Software Engineer
Kilwar LLC
- Developed and maintained high-performance Java-based financial applications, ensuring compliance with security and availability requirements.
- Led the Findur integration and optimization project, reducing processing time by 30% and enhancing system scalability.
- Designed and implemented CI/CD pipelines with Jenkins and GitHub Actions, reducing deployment time by 40%.
- Conducted performance testing and database optimizations to improve transaction efficiency and data retrieval.
- Collaborated with cross-functional teams in an Agile environment, implementing DevOps best practices.
Backend Developer
Eatcheap Agency
- Built and optimized enterprise banking applications using Java, Spring Boot, and Oracle RDBMS.
- Developed highly available and scalable services, ensuring system uptime of 99.99%.
- Led a data warehouse migration project, improving data retrieval speeds by 45%.
- Automated performance monitoring and error handling using Ansible and Terraform.
- Enhanced security measures, implementing OAuth, JWT, and API security protocols.
Software Engineer
NERDZZ Digitalagentur GmbH
- Spearheaded the migration of legacy services to containerized microservices in AWS (EKS, Lambda, API Gateway).
- Developed high-performance distributed event-driven systems with Kafka and RabbitMQ, improving message throughput by 20%.
- Integrated Cloud Native Application Protection Platforms (CNAPP) for Kubernetes security, enhancing system resilience.
- Built self-healing and autoscaling Kubernetes clusters, reducing operational downtime.
- Led architectural discussions and mentored engineers, driving innovation in the API and cloud computing space.
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 (GitHub Actions, GitLab CI) to automate deployments and testing, reducing manual effort by 15%.
- Worked in an Agile/Scrum environment, participating in sprint planning, daily stand-ups, and code reviews.
Industries Experience
See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.
Experienced in Banking and Finance (4.5 years) and Information Technology (4 years).
Business Areas Experience
The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.
Experienced in Information Technology (8 years), Product Development (4 years), Business Intelligence (2 years), Project Management (2 years), and Operations (2 years).
Summary
With over 8 years of experience in backend and full-stack development, I specialize in designing, developing, and optimizing high-performance Java applications. My expertise spans financial technology platforms, RDBMS databases, and DevOps practices, enabling the development of scalable, secure, and resilient software solutions. I have a strong background in Java, Spring, SQL, and cloud-based architectures, with hands-on experience in Findur, Endur, and performance testing. A dedicated team player, I excel in Agile environments, contributing to test-driven development (TDD) and promoting continuous integration and deployment (CI/CD) methodologies.
Skills
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
Backend Development: Java, Spring, Spring Boot, Hibernate, Rest Apis
Databases: Oracle Rdbms, Postgresql, Mysql, Sql, Data Warehousing
Devops & Ci/cd: Jenkins, Github Actions, Docker, Kubernetes, Terraform
Cloud Technologies: Aws (Ec2, Rds, Lambda, S3), Azure
Financial Technology: Findur, Endur, Financial Applications, Performance Testing
Software Development Practices: Agile, Scrum, Test-driven Development (Tdd), Clean Code
Version Control & Automation: Git, Gitlab, Bitbucket, Ansible, Ci/cd Pipelines
Languages
Education
University of Peloponnese
Bachelor’s degree · Computer Science and Mathematics · Greece
Certifications & licenses
Agile Development Certification
Institution of Peloponnese
Profile
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