Projects: OLAP backend, ETL, ML recommendation systems, R&D, other internal projects

Achievements:

— created ML product recommendation pipeline that was crunching terrabytes of raw data and served up to 1k product recommendation requests per second with response time SLA < 20ms

— created Recommendation Engine, that managed 100+ user-defined hierarchical models and served up to 1k rps with model response time under 20ms

— partially designed and worked on Analytics pipeline, that provided ETL and OLAP capabilities for billions of events per day, with petabytes of historic data and real-time reporting capabilities

Technologies: java, scala, kotlin, python, spark, spark ML, vertx, kubernetes, docker, AWS, mysql, vertica, clickhouse, cassandra, kafka, etc.

• Projects: various projects and services, such as reporting service, inventory management service, playable ads, bidders/optimizers, quota allocation service

• Team: at most 3 engineers per project

• Key achievements:

— redesigned and implemented OLAP backend, with 10x speed for some queries and extendable architecture

— created a tech stack from scratch and then successfully lead a team of 3+ people building and delivering Playable ads (a web-based replicas of mobile games)

— participated in development and optimization of an ML-based RTB bidder, a high-loaded service with billions of requests per day, reduced RAM requirements 4x

• Technologies: scala, tomcat, vertica, clickhouse, memcached, golang, python, scikit-learn, scipy, numpy, javascript, phaserjs, webgl, AWS, kubernetes, docker, etc.

• Responsibilities: full-cycle development and support of several internal projects (new features design and implementation, testing, bugfixing, performance testing, refactoring, releasing)

• Project: Velti AdServer (world's top Mobile Marketing & Advertising Platform)

• Team: 30+

• Achievements:

— as a part of a medium-sized team (6-10 software engineers) redesigned ETL pipeline for Ad Server to handle the increased traffic (up to one billion impressions per day)

— designed snowflake-like scheme in Postgres, sql-generating backend service, real-time analytics

— using extensive knowledge of the whole system was able to fix the most tricky bugs, optimize performance of critical parts, and provide L3 support

• Technologies: EJB 3, Spring (DI, Security, AOP, MVC), Hibernate, Hadoop, ehCache, Maven, PostgreSQL, H2, Voldemort, JMS, Flex, Quartz, JAX-WS, AspectJ, JasperReports, JUnit, EasyMock, etc.

• Responsibilities: delivering new features (estimation, architecture design, implementation, bug fixing), refactoring, performance optimization, L3 support, interviewing candidates.

• Projects: various websites and web applications

• Team: 5+

• Technologies: PHP, Zend Framework, PDO, JavaScript, JQuery, HTML, CSS, Memcached, Lucene, Apache, MySql

• Responsibilities: Full cycle of web sites and web applications development. Creating specifications, architecture design, database design, implementing both back- and frontend

• Achievements:

— Designed and developed a corporate CMS based on Zend Framework

— Implemented web-based hotel reservation system for partner company

— Created big number of smaller websites for partner companies

• Position: Database engineer, Software engineer

• Project: university's internal system for managing students, applicants and staff

• Team: 10+

• Technologies: MSSql Server, Delphi 5

• Responsibilities: new features implementation (including complex SQL queries, stored procedures, triggers in addition to Delphi code), legacy code refactoring, support

• Achievements:

— Successfully released several versions of the project

— Implemented trigger-based change history logger

— Improved development process in several ways