Oleg Poltoratskii

Customer: GAINSystems, Inc; Retail & Distribution. GAINS is the supply chain performance optimization company. GAINS helps companies focus on prioritizing the right decisions at the right time at the right speed and scale to optimize supply chain performance, improve profits, and boost customer confidence.

Project: Engagement to assess current legacy architecture and design new architecture, put technical foundation in place for the migration to the new architecture.

Team: 1 delivery manager, 1 solution architect, 1 data architect, 1 development team lead, 5 software developers, 2 data developers, 1 business analysts, 1 system engineer, 1 testers.

Role: Development team lead.

Tools and Technologies: Java Concurrency/Multithreading, Scale In/Out, Scale Up/Down, Spring Boot, Spring Data JPA, Spring Data Redis, Spring Cloud Netflix, Spring Cloud OpenFeign, Confluent Kafka, Redis, Kubernetes, Azure App Service, Azure App Config, Azure APIM, Databricks, PostgreSQL, Junit, Mockito, gradle.

Creating the Technical Framework for business functionality:

• Vertical scaling.
• Horizontal scaling (creating communication between instances, using Redis, and setting up Kubernetes).
• Developing a subsystem for data loading and saving with possibility to configure by developers.
• Orchestration and interaction with Databricks.
• Implementation of multitenancy, so different clients can use the service independently.
• Synchronized interaction via Kafka, going beyond standard use cases.
• Performance tuning.

Organizing the Development Team’s Workflow:

• Developing a branching strategy – defining the workflow for version control systems.
• Configuring branch protection to prevent merging code that has not passed quality checks.
• Automatic generation of code quality reports for pull requests.
• Code reviews – quality control of development code.
• Creating and configuring CI/CD pipelines.
• Deploying necessary services for development.
• Setting up launch configurations, configuring request profiles with pre-defined IDs and example queries.

Technical Leadership and Training.

Customer: EPAM Systems, Inc.; Software & Hi-Tech.

Project: The VTS application is considered a core enterprise time-off tracking system on a company-wide scale. VTS consolidates requests (leave, compensation, and deadline extension), approvals, balance calculations, and accruals to manage your vacation, sick leave, and PTO in one secure system. VTS incorporates local regulations, laws, and policies to help the company remain compliant and reduce costs.

Team: 1 delivery manager, 1 solution architect, 11 developers, 2 business analysts, 7 testers, 1 system engineer.

Role: key developer.

Tools and Technologies: Java Concurrency/Multithreading, Spring Boot, Spring Data JPA, PostgreSQL, Apache Kafka, Junit, Mockito, Gradle, Openshift.

Results: Design and implementation application/service «Data collector» - collector of user data from different sources, with filters, pre-processors, post-processors, flushers for manipulation and storing data. Handling history of employees' attributes, allowing retrospective changes. Implementation with multithreading support, concurrency, thread safety, using CAS technique and concurrent data structures, counters, semaphores, etc. Increasing throughput and performance by reducing requests to DBMS and messages for dependent services.