Dmitry Kozlov, Developer in Toronto, ON, Canada
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Dmitry Kozlov

Verified Expert  in Engineering

Bio

Dmitry is a senior big data architect with 16+ years of experience in data warehousing, BI, ETL, analytics, and the cloud. He's led teams in the delivery of 24 projects in the industries of finance, insurance, telecommunications, government, education, mining, manufacturing, and retail. Dmitry thrives in high-paced environments, has demonstrated the ability to lead effectively, manage, and support teams, and has consulted on several projects as a BI, data warehouse, and big data expert.

Portfolio

Blue Cross Blue Shield
Data Architecture, Oracle, Data Migration, Solution Design
Orbital Kitchens
Data Visualization, ETL, Data Engineering, Modeling, SQL, Tableau, Databases...
Gartner - Engineering
PL/SQL, Oracle, SQL, PostgreSQL, Amazon Web Services (AWS), Python, Terraform...

Experience

  • SQL - 20 years
  • Data Architecture - 20 years
  • Data Engineering - 18 years
  • ETL - 16 years
  • Data Warehouse Design - 16 years
  • Business Intelligence (BI) - 15 years
  • Tableau - 8 years
  • Big Data - 5 years

Availability

Part-time

Preferred Environment

SQL, ETL, Data Architecture, Big Data, Business Intelligence (BI), Data Warehousing, Tableau, Team Leadership, Snowflake, Data Analysis

The most amazing...

...and challenging project I've done was building an ETL framework for a small startup that was crucial to the company's growth.

Work Experience

Senior Solutions Architect, Migration Lead

2024 - PRESENT
Blue Cross Blue Shield
  • Led a team of developers and QA analysts in a source system migration project.
  • Designed a solution to replace a major source system for a key insurance benefit application.
  • Performed reverse engineering and data analysis for an existing Oracle application.
Technologies: Data Architecture, Oracle, Data Migration, Solution Design

Senior Data Engineer

2023 - 2024
Orbital Kitchens
  • Developed the first version of the client's corporate dashboard.
  • Created a forecast for Superbowl 2024 demand and analyzed the execution.
  • Integrated the customer historical and incremental order data.
Technologies: Data Visualization, ETL, Data Engineering, Modeling, SQL, Tableau, Databases, Snowflake

Data Engineer III

2023 - 2024
Gartner - Engineering
  • Migrated Oracle data structure and software packages to PostgreSQL.
  • Conducted extensive performance tuning on both Oracle and PostgreSQL.
  • Used Python Streamlit to create custom reporting solutions.
Technologies: PL/SQL, Oracle, SQL, PostgreSQL, Amazon Web Services (AWS), Python, Terraform, CI/CD Pipelines, Scaled Agile Framework (SAFe), Performance Tuning, Dynamic SQL

Data Analyst Engineer

2022 - 2022
Bentkey Services, LLC
  • Performed statistical analysis for Recurly subscription data integrated with Snowflake data warehouse.
  • Provided a marketing budget channel attribution analysis on Facebook and YouTube.
  • Developed video playback metadata analysis and a campaign effectiveness analysis.
Technologies: SQL, Data Analysis, Statistics, Snowflake, Event-driven Architecture, Domo, Recurly, Business Analysis, Data Analytics

Cloud Data Engineer

2022 - 2022
Vivid Machines Inc.
  • Developed complex Tableau dashboards for apple growers.
  • Designed a data model for a machine learning output.
  • Automated ETL pipelines to support the dashboards.
Technologies: SQL, Amazon Web Services (AWS), Data Pipelines, Data Engineering, Python, ETL, Data Warehousing, Data Architecture, Data Lakes, Databases, Data Modeling, Data Analysis, APIs, Tableau, PostgreSQL, Event-driven Architecture, Data Visualization, Google Cloud SQL, Google Cloud Platform (GCP)

Senior Data Engineer

2022 - 2022
SIG - Main
  • Created a tool to integrate data from Hadoop data and Oracle data marts.
  • Helped business users create custom requests from two sources.
  • Provided training to business users on how to use a new tool.
Technologies: SQL, Oracle, Oracle PL/SQL, Python, Hadoop, Spark SQL, ETL, PL/SQL, Data Warehousing, Big Data, Apache Hive, Data Pipelines, Performance Tuning, Dynamic SQL

Senior Data Architect

2021 - 2022
Canadian Apartment Properties REIT
  • Supported the enterprise architecture team on their strategy initiative phase two.
  • Designed a data model for several subject areas and created logical and physical data models.
  • Integrated several data sources into a corporate data lake.
Technologies: Azure, Azure SQL, Azure Data Factory, Data Lakes, Data Marts, Kimball Methodology, Data Modeling, Microsoft Power BI, Data Analysis, Data Governance, T-SQL (Transact-SQL)

Data and ETL Architect

2021 - 2021
Haus
  • Created an operations tracking data mart on Snowflake. Collected events from a website.
  • Created a marketing data mart to track social media spending and channel attribution.
  • Developed a Tableau dashboard for management and operations.
Technologies: Snowflake, Tableau, Amazon DynamoDB, Stitch Data, Event-driven Architecture, Data Analysis, Data Analytics

Data and ETL Architect

2021 - 2021
Standard Normal
  • Designed a data model for energy trading across five major markets.
  • Migrated legacy data from an old database to a new database.
  • Developed ETL pipelines to load trading data from source systems and provided tools for risk assessment and analytics.
Technologies: Google BigQuery, Google Cloud SQL, PostgreSQL, Microsoft SQL Server, Data Architecture, ETL, Kimball Methodology, Data Analytics, Data Pipelines, Google Cloud Platform (GCP), T-SQL (Transact-SQL)

Data and ETL Architect

2016 - 2021
Daisy Intelligence
  • Developed a fully functional ETL framework that ten developers used.
  • Designed the corporate data architecture for companies in the retail and insurance domains.
  • Led a team in onboarding 17 retail and five insurance data warehouses for clients.
  • Designed a set of Tableau dashboards to monitor the ETL framework.
  • Developed an extensive ETL package and implemented performance tuning.
  • Led the prototype development for migrating an on-premise solution to Google Cloud.
Technologies: SQL, Apache Hive, Hadoop, IBM Db2, ETL, Big Data, Data Warehouse Design, Data Warehousing, Tableau, PL/SQL, SQL Stored Procedures, Data Architecture, Databases, PostgreSQL, Data Modeling, Spark SQL, Kimball Methodology, Team Leadership, Data Analysis, Data Visualization, Data Analytics, Data Pipelines, Google BigQuery, Google Cloud SQL, Performance Tuning, Dynamic SQL, Google Cloud Platform (GCP), JavaScript

BI and Data Architect

2014 - 2016
Bayer Canada
  • Designed numerous data marts for Tableau dashboards for executives, account managers, and sales reps.
  • Led a team of onshore and offshore ETL and BI developers.
  • Addressed database and dashboard performance issues.
Technologies: Tableau, Oracle, PL/SQL, Microsoft SQL Server, ETL, Business Intelligence (BI), PostgreSQL, Databases, Team Leadership, Data Analysis, Data Visualization, JavaScript

Senior FATCA Data Architect

2014 - 2016
TD Bank Group
  • Designed, from end to end, a solution for different source systems.
  • Implemented comprehensive data modeling for a data warehouse and data marts.
  • Served as the go-to performance tuning guy and optimized complex queries and stored procedures.
  • Reviewed the data architecture, architectural blueprint, and business requirement documents.
Technologies: Oracle 12c, PL/SQL, Erwin, Business Analysis, Solution Design, Data Architecture, Data Pipelines, Google Cloud, Performance Tuning

BI Architect

2014 - 2015
Innovapost
  • Created BI semantic layer, metadata, and report definitions for RDP and BOBJ universes.
  • Implemented extensive performance tuning of Oracle data mart queries.
  • Transformed a local MS Access solution for unaddressed emails to enterprise architecture based on Oracle and the BusinessObjects server.
Technologies: Business Intelligence (BI), SAP BusinessObjects (BO), Tableau, SQL, erwin Data Modeler, Oracle, Data Marts, Kimball Methodology, Data Analysis, Data Visualization

Senior Data Architect

2012 - 2014
Intact Financial
  • Designed all layers in an enterprise data warehouse (EDW) to acquire a data feed from Guidewire ClaimCenter.
  • Ideated and designed all layers in the enterprise data warehouse (EDW) to acquire a data feed from Detica NetReveal.
  • Participated in a data warehouse enhancement initiative that replaced multiple data hubs with a data vault.
Technologies: Oracle, SQL, Oracle PL/SQL, Erwin, Data Architecture, Data Vaults, Sybase PowerDesigner, Informatica ETL, ETL, Business Analysis, Kimball Methodology, Data Governance

Senior Data Warehouse and BI Solution Designer

2011 - 2013
Rogers Communications
  • Took the business/data requirements from the business/data analysts and translated these requirements into information delivery logical designs and technical specifications that the BI designers/developers needed.
  • Led the strategy, design, and implementation of solutions in the area of business intelligence and data warehousing.
  • Designed project-based data models and added them to BI tools.
Technologies: Oracle, Teradata, Oracle PL/SQL, MicroStrategy, erwin Data Modeler, SQL Stored Procedures, Dynamic SQL

Senior ETL Developer

2008 - 2010
Bristol West
  • Performed a comprehensive data warehouse assessment.
  • Designed logical and physical data models for enterprise data warehouses (EDW) and numerous data marts.
  • Developed complex mappings and performed extensive SQL tuning and optimization on queries and PL/SQL stored procedures.
  • Led and mentored a team and created and utilized best practices documents to elicit the best team performance.
Technologies: Oracle, Data Architecture, SQL, Oracle PL/SQL, Oracle Warehouse Builder (OWB), Oracle Data Integrator (ODI), erwin Data Modeler, Kimball Methodology, Data Pipelines, Performance Tuning, Dynamic SQL

Senior Data Warehouse Architect

2008 - 2008
Vale Canada
  • Reviewed the existing Vale Canada data warehouse process documentation, development methodologies, data models, and ETL.
  • Conducted interviews with the Vale Canada technical staff to understand current data warehouse capabilities and collect future methodology and architecture requirements.
  • Participated in workshops to gather information about current data warehouse capabilities, future methodology, and architecture requirements and validate project findings and recommendations.
  • Assisted the project manager by making recommendations for methodology, architecture, and other improvements required to close internal audit recommendations.
Technologies: erwin Data Modeler, Microsoft SQL Server, Microsoft Visio, Data Warehousing, Data Warehouse Design, Data Governance, T-SQL (Transact-SQL)

Senior ETL Developer

2006 - 2008
Colleges
  • Led a team of ETL developers in the development of an increment 1 data warehouse. Scheduled, assigned, managed, and tracked their work, coordinating resources and task dependencies. Set the technical direction for team members.
  • Managed the development, quality assurance, deployment, and initial and daily load processes.
  • Developed complex mappings and performed extensive SQL tuning and optimization on queries and PL/SQL stored procedures.
  • Performed business analysis, designed data warehouse, and created mapping specifications.
Technologies: Data Warehouse Design, Data Warehousing, ETL, Oracle PL/SQL, Oracle Warehouse Builder (OWB), Oracle Designer, Data Architecture, SQL Stored Procedures, Performance Tuning

Senior Business Analyst

2006 - 2006
Brit
  • Designed overall solution requirements for claims and aggregate exposures subject areas as part of the overall BI project.
  • Gathered requirements through documentation and customer interviews and analyzed source system data.
  • Performed a logical and physical design for the data model for the data warehouse and the data marts.
  • Created numerous mapping specifications for ETL processes and composed report specifications.
Technologies: Business Analysis, SQL, erwin Data Modeler, Data Architecture, ETL Specification, Data Governance

Senior ETL Developer

2005 - 2006
TELUS
  • Led a team of ETL developers in a project-based camp. Scheduled, assigned, managed, and tracked work. Coordinated resources and task dependencies that set the technical direction for team members.
  • Collaborated with a BI team and an architect to develop high-level process designs and entity models and provided training for the support team.
  • Designed the ETL solution architecture and data architecture.
  • Developed complex mappings and performed extensive SQL tuning and optimization on queries and PL/SQL stored procedures.
Technologies: SQL, Oracle PL/SQL, erwin Data Modeler, Data Architecture, ETL, Unix Shell Scripting, Oracle Warehouse Builder (OWB)

Senior ETL Developer

2005 - 2005
CIBC
  • Developed and documented numerous extract, transform, and load PL/SQL packages for different data feeds for the Basel II project, a wholesale credit data warehouse.
  • Performed extensive SQL tuning and optimization on queries and PL/SQL stored procedures.
  • Collaborated with other team members and managed other subject areas.
Technologies: SQL, Oracle, Oracle PL/SQL, Stored Procedure, ETL, Data Warehousing, Data Warehouse Design

Senior ETL Developer

2004 - 2004
Dynamic Funds
  • Developed ETL (extract, transform, load) routines for several data marts.
  • Consulted with a team of developers regarding the development of supporting Oracle tables, indexes, views, triggers, packages, procedures, in-line functions, and SQL queries.
  • Performed extensive SQL tuning and optimization on views, queries, and PL/SQL stored procedures.
Technologies: SQL, Oracle PL/SQL, Oracle, ETL, SQL Stored Procedures, Unix Shell Scripting, Data Warehouse Design, Data Warehousing

Senior Data Application Developer

2000 - 2004
PdMAIN
  • Led and trained a team of developers, solution analysts, and support specialists for the new edition of the sequencing process for numerous implementations on different sites of TDS Automotive.
  • Created numerous PL/SQL stored program units (packages, procedures, functions, and triggers) and Oracle Forms and Oracle Reports for different modules of the PdMAIN’s ERP system.
  • Developed the complete OLTP data architecture's logical and physical design.
Technologies: SQL, Enterprise Resource Planning (ERP), Oracle PL/SQL, Oracle, Stored Procedure, erwin Data Modeler, Data Architecture, Oracle Forms & Reports

ETL Framework

One of my most challenging but successful projects was with a small startup with ambitious goals but not the ETL tool budget.

The startup's prototype solution stored procedures on IBM Db2. Their data intake was about to grow exponentially. Therefore, they had decided to migrate to a Hive/Hadoop cluster.

To satisfy their evolving needs and utilize their development team skillset, I designed and developed an end-to-end ETL framework that ran stored procedures like ETL processes in a Hive/Hadoop environment, kept all metadata on a Db2 server, and had Tableau dashboards for operational support.

This framework was able to serve a team of up to ten developers and three support operators. We used it for ETL development for 17 retail and five insurance data warehouses. Later on, we migrated it to a GCP cloud.

The ETL framework was crucial for the company's growth, allowing it to expand development and support operations for at least five years.

Senior Data Architect

I designed a distributed data model for energy trading data. I then migrated data from the legacy system to Postgres and BigQuery. I also expanded the new architecture to new trading markets and designed ETL pipelines.

Senior Tableau Designer

I designed advanced visualizations for an innovative, cutting-edge vision technology that helps fruit growers produce more food on existing acreage. The visualizations presented ML results together with accurate data in a near real-time mode.
1990 - 1996

Master's Degree in Mathematics and Computer Science

Dnipro National University - Dnipro, Ukraine

JULY 2005 - PRESENT

Oracle Certified Professional

Oracle

Tools

Tableau, Erwin, Oracle Warehouse Builder (OWB), Sybase PowerDesigner, Informatica ETL, Microsoft Visio, Microsoft Power BI, Oracle Designer, Stitch Data, Spark SQL, Domo, Recurly, Terraform

Languages

SQL, Stored Procedure, Snowflake, T-SQL (Transact-SQL), Python, JavaScript

Frameworks

Hadoop, Scaled Agile Framework (SAFe)

Paradigms

ETL, Business Intelligence (BI), Kimball Methodology, Event-driven Architecture

Platforms

Oracle, Oracle Data Integrator (ODI), Google Cloud Platform (GCP), Amazon Web Services (AWS), Azure

Storage

PL/SQL, Apache Hive, IBM Db2, SQL Stored Procedures, Oracle 12c, Microsoft SQL Server, Oracle PL/SQL, PostgreSQL, Databases, Data Pipelines, Dynamic SQL, Teradata, Google Cloud, Google Cloud SQL, Amazon DynamoDB, Data Lakes, Azure SQL

Other

Data Architecture, Big Data, Data Warehousing, erwin Data Modeler, Team Leadership, Business Analysis, Solution Design, Data Marts, ETL Specification, Data Warehouse Design, Google BigQuery, Data Engineering, Data Analytics, Data Visualization, Data Modeling, Data Analysis, Statistics, Data Migration, Performance Tuning, Data Governance, Mathematics, Computer Science, SAP BusinessObjects (BO), Data Vaults, Unix Shell Scripting, Enterprise Resource Planning (ERP), Oracle Forms & Reports, MicroStrategy, APIs, Azure Data Factory, CI/CD Pipelines, Modeling

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