Automation service for document exchange: designed and developed a microservice-based application for automating document exchange with over 1000 suppliers, manufacturers, and resellers of new and used guns. This system efficiently updates inventory of more than 1 million items four times daily and stock availability every 5 minutes, processing over 1 million requests during business hours. Resulted in a significant reduction in the Content Management team from 300+ to 50 employees;

Drop-shipping application development: supervised the development team in designing and implementing a drop-shipping application, offering the flexibility to automatically choose suppliers based on cost, shipping cost, and tax considerations, enhancing operational efficiency and customer satisfaction;

Shippers integration application: led the architecture design and development team for a shippers integration application, facilitating seamless integration with shipping partners to streamline logistics processes and improve order fulfillment capabilities.

Designed the architecture of a scalable system for comprehensive market analysis, capable of handling 200 requests per second. This system enabled the comparison and analysis of over 300,000 products and nearly 3 million variants daily against 100+ competitors, all while maintaining infrastructure costs under $1500/month;

Conceived the architectural design for a document exchange system, facilitating daily transactions of 3+ million product variants with over 1500 suppliers and manufacturers;

Architected a real-time stock check system for 3+ million product variants, ensuring updates every 5 minutes from over 1500 suppliers;

Devised the architecture for a drop-shipping system serving over 700 suppliers, integrating automated decision-making for optimal order fulfillment strategies;

Developed the concept and architecture for a monitoring system with price change history diagrams to aid in dynamic pricing and market positioning.

Python proficiency: mastered the Python programming language within three months, culminating in the successful completion of the Expert level certification, demonstrating a commitment to continuous learning and skill development;

Online store platform enhancement: led a team in the development of an online store platform for customers, significantly improving accessibility and usability for over 10,000 employees across 179 subsidiaries in 12 countries, enhancing productivity and efficiency;

Frontend microservice architecture: designed the architecture of a frontend microservice application using Single-SPA, facilitating the seamless integration and support of modules from the store on different frameworks, enhancing flexibility and scalability;

Microservices and serverless architecture: Architected multiple microservices and serverless applications on Go Lang, leveraging modern architectural patterns to enhance scalability, reliability, and performance.

Built a suppliers integration system, which successfully imports over 100,000 products from more than 500 suppliers and manufacturers, significantly expanding product offerings and streamlining inventory management;

Developed social network authentication using OAuth, streamlining the login process for users. Integrated 5 payment systems, offering users a wide range of payment options for flexibility and convenience;

Developed a personal cabinet for users, featuring payment history, order history, payment methods, receipt generation, and product catalog filters, significantly improving user engagement and satisfaction.

System Architecture and Development: led the development of a scalable system from scratch in the IoT department, handling rapid growth from 0 to over 500,000 clients in 4 years with more than 100,000 active daily users and more than 1,5 million active devices;

Infrastructure Management: implemented Infrastructure as Code (IaC) practices and Kubernetes clusters, ensuring efficient resource deployment, scalability, and system stability during periods of significant growth.

Disaster Recovery Planning: developed and implemented a comprehensive disaster recovery plan, ensuring business continuity and data integrity in the face of unforeseen events.

Project Stability: ensured the stability of the project, achieving and maintaining high availability even under the strain of significant user and device load.

Team Leadership: successfully managed and led cross-functional teams, including backend, frontend, and DevOps, fostering collaboration and ensuring the smooth execution of projects; provided mentorship and guidance, contributing to the professional growth of team members.

Microservice architecture transformation: Orchestrated the transition of a high-load monolith application into a scalable microservices architecture, resulting in a 3 times decrease in infrastructure costs. Mentored and supervised engineering teams throughout the process, optimizing third-party client interactions through Kafka implementation, leading to a fivefold increase in communication speed;

Scalable project architecture: designed and implemented scalable architectures for 4 projects, accommodating up to 100,000 daily users while ensuring ease of scalability to meet future demand, laying the foundation for sustainable growth and performance;

Client contract success: Influenced the successful closure of six client contracts by analyzing business requirements and proposing optimal solutions for system architecture, technology, and engineering resources, ensuring alignment with client needs and project objectives;

Team leadership development: identified and nurtured talent within the organization, elevating three team members to leadership positions from mid-to-senior levels, fostering a culture of growth and excellence within the engineering teams;

Project team building: Established and led engineering teams for multiple projects across various domains, ensuring the alignment of team capabilities with project requirements and objectives;

Designed and implemented SmileFood Courier, a comprehensive delivery logistics application, optimizing routes for couriers, enabling real-time customer updates, and providing a management monitoring system to oversee courier activity, delivery timings, and operational metrics for up to 130 couriers simultaneously across 2 cities;

Created a backend API for Wigwam, an iOS and Android application for corporate SIP telecommunication, designed to support a stable connection for up to 300,000 clients simultaneously;

Architected and developed the backend for SmileFood, an online Asian food ordering application, achieving over 80,000 users;

Developed a proprietary CMS based on the Symfony framework, powering over 80 websites;

Built Sharff, a fully automated system for ordering products from US online stores and delivering them to Ukraine, processing over 10,000 orders monthly. Additionally, developed an online store showcasing products in stock;

Designed the architecture and built a website with CRM for the first corporate debts market in Ukraine, attracting 5,000 active daily users and listing more than 200,000 corporate debts within its first year.

Developed a flexible booking system for the hotel's website using the eZ Publish framework, significantly improving the reservation process for guests;

Built the frontend for a mobile application, enabling hotel guests to seamlessly order room service, manage and pre-order services, reserve restaurant tables, and control IoT devices in their rooms among other functionalities.