Volodymyr Kopchuk

Designed and implemented scalable, high-availability systems using modern software architectures and industry best practices. Delivered end-to-end solutions using microservices architecture, REST/gRPC APIs, and event-driven systems with strong focus on performance and reliability. Developed and optimized backend services primarily using Java/Kotlin and Node.js, with select services and internal tools implemented in Go, Rust, and Ruby to address performance, concurrency, and maintainability requirements. Designed data-intensive applications using SQL and NoSQL databases (PostgreSQL, MySQL, MongoDB, Redis), including schema design and query optimization. Built and maintained CI/CD pipelines using Git, Docker, Kubernetes, Jenkins, and GitHub Actions for automated testing and deployments across AWS, Azure, and GCP. Collaborated closely with product managers, QA, and DevOps teams, conducting code reviews, mentoring engineers, and owning features from design to production.

Developed and maintained full-stack applications, building back-end services and APIs with Node.js (Express), Python (Django/Flask), and Java (Spring Boot), and integrating them with front-end interfaces built using React and modern JavaScript. Built RESTful APIs with authentication and authorization mechanisms (JWT, RBAC) and secure data exchange. Implemented back-end logic for data synchronization, background processing, and real-time features using Spring Boot services, Python-based workers, WebSockets, and Firebase. Participated in system and API design reviews, investigated production issues, and contributed to performance tuning of Node.js and Spring Boot services. Worked closely with frontend, QA, and DevOps teams across multiple environments to support deployments and production releases.

Designed and developed multiple production Android applications using Kotlin and Java following MVVM/MVI and clean architecture principles. Implemented offline-first data synchronization, background processing with WorkManager, and real-time updates. Built modern user interfaces using Jetpack Compose and XML with Navigation Component, Data Binding, and Material Design. Contributed to cross-platform mobile development using React Native, including Android build configuration, native module integration, and performance tuning. Optimized data layers using Room, Retrofit, OkHttp, Coroutines, and Flow for efficient networking and concurrency. Integrated Firebase services (Auth, Crashlytics, Analytics, FCM), third-party SDKs, payment systems, and location services. Performed performance optimization, memory leak analysis, code reviews, and mentoring of junior developers.