Sergey Filin | Сергей Филин

Real-time ad bidding platform. RTB ecosystem including own SSP and DSP.
I worked on the advertisers' self-service area, reporting interfaces and payment-related integrations,
while improving statistics presentation from distributed data sources and internal product interfaces.
I updated CI/CD infrastructure, migrated services to Docker, carried out deep refactoring
and upgraded projects to current language and runtime versions.
I also investigated and refactored a high-load Go service responsible for advertising auctions,
improving the reliability and performance of the bidding flow.

The largest platform for fanfiction authors and writers.
I worked on backend functionality using Symfony and MySQL,
refactored existing services and implemented integrations with external APIs.

Startup specializing in the implementation of cloud technologies in the financial sector.
My responsibilities included prototyping client-facing applications and backend services,
integrating the AWS technology stack across application layers
and using TypeScript with AWS Lambda for data storage, authorization, and processing.

Engaged in full-cycle game projects, including game design, project leadership, and infrastructure decisions,
by leveraging Node.js, web technologies, and the Godot engine
to build and optimize interactive experiences with real-time functionality and robust performance.

Game studio.
I contributed to the company's main game series, Magic Seasons(Ёлочка 2020-2021).
It has been a TOP-1 game on VK (vk.com) and OK (ok.ru) social networks for over 7 years.
I worked on server-side systems, optimizing and refactoring the codebase and integrating parts of the Symfony framework into the project. I worked closely with MySQL and MongoDB databases and developed a distributed transaction system spanning over different databases. Worked on integrating new features via social networking APIs.

This was a large project including an advertisers' self-service website with advanced reporting tools, payment gateway integrations, a Java bidding cluster, and distributed databases in MySQL and ClickHouse (400TiB+ of data).
I worked on personal accounts, promo codes and payment system integrations. I was also responsible for statistics and data presentation from distributed sources using complex SQL queries. I improved database structures, connected aggregation tables, handled data normalization, and assisted other campaign projects with databases and payment APIs.

Web studio.
Worked on CRM systems and multi-tenant eCommerce systems. Designed databases, payment systems, mailing lists, and integrations with external API services for payments, maps, weather, delivery etc.
Integration of 3D tours on customer sites.

Provided engineering services for various advertising and web-based initiatives,
focusing on server-side logic, databases, integrations and client-side support. Used Yii (1 & 2), Symfony, and Bootstrap,
performed refactoring and migration tasks, implemented site parsing with Python/PHP and Gearman,
and integrated external APIs (maps, weather, etc.).