Roman Shageev

Designed and developed scalable microservice architectures using Java 21, Spring Boot, Spring Data, and
Hibernate
• Architected and implemented a dynamic Excel report generation service from scratch using a streaming data
approach (PostgreSQL + Apache POI), resolving critical OOM issues and enabling
stable exports of 50k+ rows under strict memory constraints (1 GB RAM)
• Implemented dynamic filtering mechanisms, a custom attribute evaluation layer, and consolidation logic for
complex queries with dynamic column sets
• Configured asynchronous service-to-service communication via Apache Kafka and REST
• Orchestrated distributed scheduled tasks using Spring Scheduled and ShedLock
• Participated in system analysis, led comprehensive code reviews within a 10-member cross-functional team
• Regularly initiated codebase refactoring focused on Clean Code principles and long-term maintainability
• Ensured high stability of developed modules through comprehensive unit and integration testing

Project 3: Preschool Enrollment Application Processing (Python / Legacy Support)
• Independently mastered Python to reverse-engineer and analyze a complex, undocumented legacy system
inherited from a third-party vendor.
• Localized and resolved critical production incidents, building a suite of custom Python scripts for live hot-fixes in
the production environment.
• Analyzed the underlying custom framework and successfully deployed new features using Python, Django, and
Celery.
• Documented the system architecture, business logic, and deployment workflows from scratch, successfully
onboarding team members for subsequent project maintenance.

Project 1: CRM System for Ticket Processing & Telephony Integration
• Designed from scratch and refactored existing microservices using Java 11 and Spring Boot.
• Built a fault-tolerant asynchronous Notification Subsystem processing over 5,000+ daily
notifications across Telegram, SMS, Email, and HTTP channels.
• Optimized heavy PostgreSQL queries and refactored a complex dynamic SQL function
• Developed an email processing integration module via IMAP/POP3/SMTP using Spring Integration and designed
the architecture for corporate Telegram bots.
• Maintained high code quality and architecture transparency using JUnit, Mockito, Swagger, and JavaDoc.

Project 2: Real-Time Call Center Monitoring Subsystem
• Architected from scratch and developed a 3-microservice complex using Java (Spring Boot) and PL/pgSQL:
◦ Core Metrics Service for API data storage
◦ Data Collection Service
◦ BFF adapter service to aggregate time-series data and dynamically serve UI
dashboard components.