Leonid – MySQL, SQL Server, Redis

Custom enterprise software for mid-size and enterprise clients, including retail systems that connect ERP with point-of-sale terminals and an ESG data collection platform for corporate sustainability reporting.

• Owned the system architecture and technical decisions across several client projects, from discovery to production release.
• Designed near-real-time messaging between ERP and POS terminals on message brokers, preserving message ordering and reliable processing.
• Ran requirements analysis, data model and integration design, and technology selection for each project.
• Set up DevOps and deployment pipelines for .NET and Angular solutions.
• Led and mentored development teams, ran code reviews, and set quality and testing standards.

A microservice-based audit platform on AWS for a banking client that ingested large volumes of financial data from external sources and published entity changes to downstream systems.

• Led a team of developers, analysts, and QA engineers on the audit project.
• Redesigned how the ingestion service published entity changes downstream, moving it to a mediator/DDD approach with create, update, delete, and publish events.
• Built event-driven messaging on Amazon SNS/SQS FIFO with dead-letter queues, retry logic, and a Lambda-based redrive, storing large payloads in S3 and sending only identifiers through the queues.
• Implemented the outbox pattern and Redis-based distributed locking to keep data consistent across services.
• Developed back-end services in .NET and front-end features in Angular, working with Elasticsearch and MySQL data stores.
• Handled DevOps tasks, release management, and resource planning for the team.
• Worked directly with the customer to negotiate requirements and plan releases.

A microservice-based website builder that let users create multi-language sites, edit page structure, customize themes, and publish sites, with centralized access management.

• Developed back-end services and front-end features for the site builder.
• Contributed to architectural decisions for the microservice-based solution.
• Containerized services with Docker and Kubernetes and configured CI/CD pipelines.
• Mentored junior developers and planned team tasks.
• Wrote tests, fixed bugs, and communicated with the customer on requirements.

A high-load casino management system with a web application for administering a casino network and a desktop application for gaming machines integrated with player tracking systems.

• Developed back-end and front-end features for the casino network administration web application.
• Built functionality for the gaming machine desktop application and its integration with player tracking systems.
• Contributed to architectural decisions for the solution.
• Configured CI/CD pipelines and wrote tests.
• Mentored junior developers, planned tasks, and fixed bugs.

A SaaS CRM and business process management platform customized to the workflows of individual client companies.

• Implemented client-specific business logic with the platform's low-code BPM tools.
• Deployed the CRM system on client infrastructure.
• Managed and maintained client databases.

A password management system for iOS and macOS that combined a mobile app with a browser extension and transmitted data over encrypted Bluetooth connections.

• Developed a Google Chrome extension for web page analysis.
• Built testing tools for the Google Chrome and Safari extensions.