Drazen Zaric, Data Scientist and Machine Learning Developer in Belgrade, Serbia
Drazen Zaric

Data Scientist and Machine Learning Developer in Belgrade, Serbia

Member since May 30, 2019
Drazen is a data scientist and data engineer with over seven years of experience building analytics infrastructure, machine learning, and data analysis. He has extensive experience in big data, machine learning, and web development. He has worked with notable companies such as Slack and Microsoft, and built products used by millions of users.
Drazen is now available for hire

Portfolio

  • Teespring
    Tableau, Data Visualization, Data Science, Python, Redshift, Snowflake
  • Freelance Consultant
    Tableau, Big Data, SQL
  • Nordeus
    Apache Impala, Hadoop, Aerospike, JavaScript, Python, Java

Experience

Location

Belgrade, Serbia

Availability

Part-time

Preferred Environment

Vim Text Editor, Python, Linux, MacOS

The most amazing...

...project I've built was an analytics infrastructure for a product with 150 million users.

Employment

  • Data Scientist

    2019 - 2020
    Teespring
    • Worked as part of the data team. Developed dashboards (Tableau) and data reports (Redash), and worked on migrating from Redshift to Snowflake.
    • Supported commercial and partnerships teams with data insights.
    • Developed an interactive real-time map visualization of Teespring sales (JavaScript and Mapbox).
    Technologies: Tableau, Data Visualization, Data Science, Python, Redshift, Snowflake
  • Analytics Consultant

    2019 - 2019
    Freelance Consultant
    • Collaborated with small companies on establishing their data infrastructure, discipline, and teams.
    • Assessed existing processes, available data, and infrastructure.
    • Planned for future growth in terms of product, and the team.
    • Helped with descriptive and predictive user behavior models, segmentation, and A/B testing.
    Technologies: Tableau, Big Data, SQL
  • Product Manager

    2017 - 2018
    Nordeus
    • Led the team in developing Golden Boot, a game for a then new platform called Facebook Instant Games. This product grew from an idea to over 10 million players in four months.
    • Oversaw the product and project management, back-end development, data analysis, and game design within an Agile team.
    • Developed high performance algorithms for matchmaking.
    • Developed a distributed push notifications system backed by a Hadoop data warehouse and a machine learning model for user churn.
    Technologies: Apache Impala, Hadoop, Aerospike, JavaScript, Python, Java
  • Data Scientist

    2015 - 2017
    Nordeus
    • Developed internal data products. Designed, developed, and deployed optimization algorithms for in-game tournament generation.
    • Developed machine learning models for anomaly detection, product performance and user behavior prediction, tools for optimizing marketing campaigns.
    • Maintained and improved a custom, in-house BI tool.
    • Supported product managers, game designers, and user acquisition teams with analyses, and insights.
    Technologies: Pandas, NumPy, Scikit-learn, Flask, Tableau, SQL, Machine Learning, Python
  • Data Engineer

    2013 - 2015
    Nordeus
    • Developed and maintained an in-house ETL system, and data warehouse on top of Hadoop and Impala for TopEleven, an online game with over 150 million players.
    • Transitioned a single PostgreSQL instance to an in-house Hadoop cluster solution.
    • Designed and wrote data import and SQL transformations, and oversaw the data quality.
    • Integrated data from internal and third-party data sources.
    • Scaled data warehouse and processes from a single product, to multiple products.
    Technologies: Hadoop, SQL, Python, Data Engineering
  • Software Development Engineer

    2011 - 2013
    Microsoft
    • Developed the PDF Reflow feature for Word 2013.
    • Designed algorithms for converting a PDF into an editable DOCX document.
    • Implemented and evaluated machine learning models for identifying parts of a PDF document.
    Technologies: C++

Experience

  • Blogboard (Development)
    https://blogboard.io

    Blogboard is a search and discovery engine for official blogs of leading tech companies.

    As a solo creator, I've worked on front-end development (Vue.js), back-end, and search (Python, PostgresSQL, Elasticsearch). I also write the official product blog (linked above).

  • Top Eleven by Nordeus (Development)
    https://www.topeleven.com/

    A highly successful online sports games, Top Eleven has had over 150 million players to date. I worked on the analytics infrastructure, product management, data science, and in-game algorithm development.

  • Votum Polls for Slack (Development)
    https://votum.app

    This is a Slack app I developed end-to-end, enabling the polling and running of idea tournaments within Slack.

  • Selecta: An Amarok Player Extension (Development)
    https://github.com/drazenz/Selecta

    This is an inverted index and tf-idf retrieval engine for music in your library based off Last.fm tags. This was implemented from scratch in JavaScript, done back in the days when music was offline.

  • Improved Heatmaps in Python (Development)
    https://github.com/drazenz/heatmap

    This is a Python code, and a Jupyter notebook for an improved heatmap implementation using Matplotlib and Seaborn.

    Similar to what you can easily get in Tableau using a Size parameter, here you can have a square as a parameter depending on the field value.

    Described in detail in this blog post: https://towardsdatascience.com/better-heatmaps-and-correlation-matrix-plots-in-python-41445d0f2bec

Skills

  • Languages

    Python, SQL, C++, JavaScript, Snowflake, Java
  • Frameworks

    Flask, Hadoop
  • Libraries/APIs

    Scikit-learn, Pandas, NumPy, Vue.js
  • Tools

    Apache Impala, Tableau, Ansible, Vim Text Editor
  • Paradigms

    Data Science
  • Other

    Data Engineering, Machine Learning, Algorithms, Data Visualization, Optimization, Big Data, Front-end, Back-end, Technical Writing
  • Platforms

    Linux, MacOS, Apache Kafka
  • Storage

    PostgreSQL, Aerospike, Redshift, Elasticsearch
  • Industry Expertise

    Web Development

Education

  • Master's degree of Science in Computer Science
    2010 - 2011
    University of Novi Sad - Novi Sad, Serbia
  • Bachelor's degree in Computer Science
    2006 - 2010
    University of Novi Sad - Novi Sad, Serbia

Certifications

  • Product Management Program
    JANUARY 2019 - PRESENT
    UC Berkeley Executive Education

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