Dideo - Ultimate Video Search EngineDideo is a powerful meta video search engine with access to more than 5 billion videos on the web. More than 8 million users watch at least 25 million videos per month on this platform. Responsibilities:• Led and supervised a team of ten software developers in creating a robust upgraded version of the Dideo website.• Redesigned and significantly optimized the Dideo parent safety service by implementing memory caching techniques and introducing the Sanic framework, resulting in a threefold performance improvement.• Redesigned the micro-service architecture of the entire system to ensure efficient horizontal scaling capabilities.• Developed and implemented a highly eficient video cache service, reducing external traffic utilization from video providers by 50% and enhancing user experience with an internal CDN.• Introduced and established an A/B testing environment that enabled the discovery of product prices, leading to a 15% increase in sales.• Built and deployed Docker containers for Dideo CDN video servers, significantly enhancing scalability and reducing deployment time.• Assisted in the development of a service built on top of Elasticsearch to optimize the search functionality and enable relevant video suggestions within the website.• Contributed to the setup, maintenance, and monitoring of a network comprising more than 20 Unix servers, ensuring an impressive uptime of 99%.• Developed a robust backup system, ensuring regular backup and restoration of databases to address emergencies effectively.Technologies include:• PHP, Python• Laravel, Lumen, Sanic Frameworks• MySQL, MariaDB• ElasticSearch• Redis as hand-held data store as cache server• Docker, docker-compose• Nginx, HAProxy• vSphere, pfSense• Zabbix

Realiff - The professional real estate social network.Realiff is a marketplace for real estate agents that connects people looking to purchase or sell a house with top real estate agents in their area who compete for their business.Responsibilities:• Provided guidance to junior developers in application development and architectural decision-making for the Realiff website.• Led and successfully launched the Realiff website in 8 months.• Developed a robust recommender system to match clients with the most suitable agents based on their unique preferences.• Developed a crawler to retrieve comprehensive agent proles, collecting information on over 500K agents across the USA.• Supervised the UI modiffications for website sections, optimizing page performance for faster loading and browsing, resulting in a significant 60% increase in page speed.• Implemented a mail server and developed an email service to facilitate the delivery of both transactional and promotional emails.• Developed an RSS crawler to fetch the most recent items relevant to user preferences, ensuring users stay updated with the latest offerings.Technologies include:• PHP, Python as the main programming languages• Laravel, Scrapy Frameworks• MariaDB database management system for storing metadata• Pusher to manage real-time events.• Gitlab as the issue tracking/SCRUM tool• Outline as a team knowledge base for documentation

Giftpals - Retail Luxury Goods and JewelryGiftpals assist customers in finding the ideal present. GiftPals helps shops take advantage of the income potential of social and mobile commerce by giving customers a pleasant and sociable gift-giving experience.Responsibilities:• Managed a team of eight developers, providing guidance and conducting timely reviews of developed modules.• Led and the successfully launched the Giftpals website in six months.• Developed and maintained highly scalable, high-performance, and highly available search indexes utilizing ElasticSearch.• Implemented an efficient offline recommender system to find related products and create personalized user feeds.• Designed the website’s entity-relationship and object-relation models, ensuring optimal functionality and data organization.Technologies include:• PHP as the main programming language• Laravel Frameworks• npm, Composer to manage project dependencies • Supervisor to manage jobs• ElasticSearch to store user interactions