UnifyOrdering Ltd is an Irish e-commerce startup automating ordering processes for over 10,000 users, 4,500 buyer companies, and 500 suppliers (including big names like Coca Cola), transacting €20,000,000 monthly.- Developed a subsystem to integrate with suppliers' business systems (data exchange automation), resulting in a 12% increase in paid subscriptions.- Designed and developed an automated pipeline to process and reconcile vendor invoices using optical character recognition, accelerating the reconciliation process by approximately 10x.- Designed and developed over 15 microservices, migrating some functionality from the monolith, which increased system stability.- Improved microservice observability with logging, metrics, and traceability by integrating the Grafana stack.- In collaboration with the DevOps team, initiated and implemented the migration from AWS ECS to AWS EKS. This resulted in a simplified deployment process: developers were able to make changes themselves, and DevOps improved support efficiency due to their Kubernetes experience.- Optimized the CI/CD pipeline, reducing build and deployment times by a factor of 5 and dramatically improving the speed of change delivery.

Infinet Wireless is an international leader in broadband wireless access equipment, providing high-performance data, voice, and video solutions in over 130 countries worldwide.- Developed a microservices-based architecture using Go, PostgreSQL, Kafka, Docker, and Clickhouse to monitor wireless broadband equipment, resulting in the monitoring of over 50,000 devices worldwide.- Designed and built a log collection service that reduced customer storage costs by 200x using ClickHouse.- Redesigned telemetry polling subsystem code for wireless devices, increasing throughput by 3x (5,000 to 15,000 devices per installation).- Served as technical lead for a team of 8 backend developers and focused on architectural decisions, code quality, and technical mentoring.- Implemented a culture of writing guides and documentation within the team and actively promoted the practices of code review, testing, and technical reviews of projects to maintain a consistent ideology. This resulted in improved code quality, consistency in development practices, stronger team collaboration, and a much faster onboarding process for new team members.- Integrated the Bazel build system, which reduced build time by 30% and improved local builds by 50%, increasing CI/CD efficiency and accelerating releases.

InfiPLANNER is a radio planning tool from Infinet Wireless that helps network engineers simulate and optimize wireless networks by taking into account factors such as terrain, frequency and distance. It allows users to predict link quality and efficiently design reliable wireless systems.- As the sole backend developer, I collaborated with a team of scientists and frontend developers to develop the InfiPLANNER system, which reduced the technical support workload by 10% and contributed to a ~8% increase in the customer base.- Achieved to 80% code coverage with automated testing, ensuring uninterrupted service operation for the past 7 years.- Improved the company's infrastructure, simplified access management, increased security, and made it easier for users to access services by consolidating 4 existing authentication systems into a unified SSO solution with Keycloak.- Streamline and simplify the entire deployment process by automating the deployment of internal services through Ansible integration.

CityCall is one of the top 5 call centers in Russia, with more than 1,200 workstations and 1,800 employees in 14 cities, capable of handling up to 550,000 calls per day. - Architected and designed the REST API for a workforce management system that allows call center managers to effectively plan staffing needs, manage workloads, and schedule employees.- Developed, tested, and optimized the backend using Ruby on Rails with PostgreSQL as the database to ensure high performance and scalability.- Built a Python Twisted service for seamless integration with the call center platform, enabling real-time data exchange and synchronization.- Ensured a smooth and efficient production rollout by deploying the solution in Docker containers and automating deployment via Ansible.- Worked closely with the client to gather requirements, provide technical support, and deliver continuous improvements, resulting in a system that is still highly successful and actively used over a decade later.- The modular design of the system made it easy to scale and adapt, making it a long-term solution to continue to meet evolving business needs.

Ideco is a developer of solutions for traffic filtering and network protection, whose products are used by over 5,500 companies.- Developed and refactored modules for the Ideco ICS Internet Gateway, providing secure Internet access and protection against electronic threats, using C, Bash, and Firebird.- Participated in the design of new functionality, contributing to the evolution and improvement of the system.- As lead developer for the Ideco PBX IP telephony server, designed the architecture for front-end and back-end interaction, driving the development of a box solution for small and medium businesses.- Developed key backend subsystems such as LDAP-based address books, a RADIUS statistics module, and Asterisk monitoring to ensure robust communications management.- Integrated version control with Git, trained the team, and migrated existing code into repositories.- Implemented Python for both application and system programming, modernizing the development stack and improving overall productivity.