Sergey Lotnikov

• Analyzed current architecture of data warehouses and ETL processes.
• Evaluated new features of Databricks cloud data platform to make improvement recommendations.
• Designed solutions in data engineering, data operations and devops areas to streamline data processing.
• Optimized workloads and improved efficiency in terms cost and performance by identifying and removing bottlenecks. Max achieved cost decrease was more than $1000 per day.
• Participated migration projects from legacy platforms to modern cloud, including ETL configurations rebuild.
• Participated international integration project, analyzed data processing methodology and infrastructure in US and EU markets in order to merge them into single cloud data platform.
• Developed Automated Data Catalog solution based on Python and Neo4J graph database, intended to simplify understanding the dependencies between data and ETL steps, centralize and automate data and pipelines documentation, improve data engineering work and boost newhires onboarding process.

• Led a team of data operations engineers who maintained cloud data platform consisted of several legacy data warehouses, complicated legacy ETL infrastructure based on wide range of technologies and migrated all this to new cloud enterprise data platform based on Databricks on AWS.
• Became Subject Matter Expert in many company's business areas.
• Trained junior engineers on standard data operating procedures, contributing to a knowledgeable and skilled workforce.
• Streamlined workflow processes, resulting in improved overall team efficiency and effectiveness.
• Hired, onboarded and mentored about 7 new team members.
• Resolved hundreds of data operations tasks: data investigations, manual fixes and backfills using SQL, Spark, Talend, SSIS and many other technologies in many databases and warehouses - Databricks, Teradata, Snowflake, MySQL, MSSQL, Sybase.

• Maintained complex data warehousing and data processing platforms based on different technologies, modern and legacy, in the cloud and on premises, for the company working in the entertainment domain.
• Conducted root cause analysis for data quality issues, resulting in long-term solutions and improved system stability.
• Designed runbooks to help team provide optimal service uptimes and minimize service disruptions.
• Participated the migration of legacy on premises systems to modern cloud platforms, ensuring minimal disruption to business operations during the transition process.
• Built tools for metadata analysis to identify performance and costs trends in production and development environments, to help management optimize the system proactively.
• Collaborated with cross-functional teams to develop and implement changes in ETL pipelines.
• Monitored and optimized production processes to increase throughput and improve quality.
• Reduced downtime in production environments through proactive monitoring and timely issue resolution.
• Troubleshot complex issues under tight deadlines, prioritizing tasks effectively to minimize disruptions to ongoing operations.

• Implemented many projects in mobile telecommunications domain: Fraud Management, Revenue Assurance and Usage Control, Dealer Commissioning solutions for customers in many countries.
• Collaborated with customer's business teams while analyzing business requirements, evaluating client needs and expectations and designing solution's architecture.
• Collaborated with customer's technical teams to successfully deliver and integrate solutions into customer's environment.
• Managed client relationships through regular check-ins and updates on project progress.
• Designed and implemented Data Models, ETL pipelines, interactive web interfaces and reports using highly customizable low-code instruments.
• Deployed and tested solutions on development and productive environments, on-site and remotely.
• Provided technical support and further development of delivered solutions.

• Started and developed a regional division of the company to support big network of POS-terminals and Automated Gas Station Control Systems on customer's gas stations network over the area of 1M square kilometers
• Maintained local Cards Processing Center - supported the process of fuel and loyalty cards emission and acquiring, supported local data warehouse
• Interacted with customer's regional department daily to support relationships and ensure division meets all required SLAs.
• Managed the process of installation, technical support, maintenance and permanent repair of terminals and communication equipment on gas stations.
• Performed data quality control and manual data corrections in case of any discrepancies found in the warehouse.
• Negotiated, created and tuned discounting tariff plans with complicated business rules for corporate customers monthly.
• Hiring, onboarding, mentoring of new people
• Performed finance and administrative tasks: office rent, fuel, mobile and office communications, data center colocation services, etc.

• Provided billing system (OSS/BSS) technical support and exploitation: mobile calls processing, subscribers relations management and other subsystems in a huge mobile company (about 100M subscribers).
• Worked with large volumes of data in Oracle database, developed stored procedures and packages on PL/SQL. Configured and supported of microservices software based on .NET services, ASP.NET web-services, MSMQ, etc.
• Coordinated system updates, orchestrated patch set installations through many physical servers, logical subsystems and teams
• Performed testing, troubleshooting, temporary solution development, interacted with software development center upper level technical support
• Took part in OSS/BSS integration projects over many countries and regions: performed installation planning, subsystems deployment orchestration, interconnections and data flows setting and tuning, on-site technical support
• Documentation development (logical data flows, network diagrams, system architecture diagrams, integration manuals, user manuals, and many others
• Lead local on-site integration team, mentoring
• Performed business analysis, proposed solutions to improve system architecture to fit new business-requirements
• Managed country-wide project for billing system swap for local mobile operator
• Participated pre sales demo project in Wateen Telecom project in Lahore, Pakistan
• Participated Intelligent Network (IN) platform integration project

Performed administrative tasks for Automated Banking System:

• Data consistency control
• Non-standard data queries in Oracle
• Users administration
• Designed solutions and proposals for banking software updates. Performed functional analysis of Automated System in order to comply with Central Bank requirements.
• Took part in a new Automated Banking System development as system analyst.
• Developed reporting software for internal use on Oracle PL\SQL and Delphi