Miroslav Maraz, Developer in Philadelphia, PA, United States
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Miroslav Maraz

Verified Expert  in Engineering

Software Engineer and Developer

Philadelphia, PA, United States
Toptal Member Since
June 18, 2020

Miro is a versatile software engineer with a mix of skills ranging from application development to data engineering and data science. He has 15 years of experience building and delivering data-driven applications to clients of all sizes. He is extremely flexible and able to work as a standalone freelancer or integrate within teams. Miro currently builds intelligent web applications and APIs with embedded smart algorithms and machine learning.


Untitled Research
Docker, Angular, JavaScript, HTML, PostgreSQL, SQL Server 2016, C#, R, Python
Coldlight | PTC
Amazon Web Services (AWS), Tableau, Java, Python, C#, MongoDB, MySQL...
Connolly (Cotiviti)
Pervasive PSQL, Full-stack, SQL, HTML, R, OLAP...




Preferred Environment

RStudio, PyCharm, Spyder, Visual Studio Code (VS Code), Visual Studio

The most amazing...

...project I've architected was a smart healthcare platform that combined medical data from 160 million individuals with machine learning to predict various risks.

Work Experience

CTO | Lead Architect

2015 - PRESENT
Untitled Research
  • Created a predictive API with Python, Flask, MongoDB, PostGres, and H2O.ai.
  • Designed a desktop master data management application using C#, SQL Server, Entity Framework and DevExpress components.
  • Developed a responsive Angular application for movie data.
  • Created an internal toolkit based on R Server, SQL Server 2016 and H2O that enables rapid development of predictive models and collects supporting data and metadata.
  • Crafted interactive noetebooks that visualized historic data for a music industry client with R Markdown, Bootstrap, Plotly, and Impala SQL.
Technologies: Docker, Angular, JavaScript, HTML, PostgreSQL, SQL Server 2016, C#, R, Python

Technical Director | Data Services

2014 - 2015
Coldlight | PTC
  • Architected a database system that collected 1.1 billion+ healthcare transactions and events for 160 million individuals with Talend and Amazon Redshift.
  • Created a metadata-driven feature engineering and data transformation utility capable of transforming raw data into input features for a machine learning process.
  • Created several workflows in Talend that interacted with several database systems and machine learning and persist the results of machine learning processes.
  • Oversaw an implementation of a Talend-based master data management solution that replaced proprietary, labor intensive solution.
  • Assisted colleagues from various departments to optimize data engineering and data transformation techniques and methods.
Technologies: Amazon Web Services (AWS), Tableau, Java, Python, C#, MongoDB, MySQL, PostgreSQL, Microsoft SQL Server, Redshift, Talend

Lead SQL Developer | Technical Data Analyst

2009 - 2014
Connolly (Cotiviti)
  • Led the re-engineering effort of a 6+TB data warehouse that enhanced performance while reducing storage footprint by 20%.
  • Designed a custom, data collection framework that enabled collection of previously unattainable information from 3rd party systems access with AutoIt, SQL Server, and PowerShell.
  • Implemented various enhancements and optimizations to SQL based ETL processes to enhance performance and reduce processing time by 63%.
  • Developed various data mining analysis of healthcare claim data aiming at identifying anomalies with SQL Server SSAS Data mining algorithms.
  • Created a custom rule engine with XML based storage and SQL based execution that allowed users to create, store and execute business rules against the data warehouse and find qualifying records.
  • Authored and lectured a SQL server advanced course for an internal team of SQL developers.
Technologies: Pervasive PSQL, Full-stack, SQL, HTML, R, OLAP, SQL Server Integration Services (SSIS)

Software Engineer | Data Architect | Co-founder

2006 - 2009
KRESS, Slovakia, EU
  • Designed a custom data processing and master data management platform that integrated pharmaceutical sales, logistics and CRM data with VB.NET, DevExpress, and SQL Server.
  • Led the development of a data analysis tool that allowed 400+ users to explore and visualize millions of rows of sales data offline with a proprietary ROLAP technology.
  • Created a GIS-based mapping module that enabled the end users to customize maps and create and analyze sales across custom regions.
  • Automated data aggregation processes used to create offline cubes with metadata driven by using VB, SQL Server, and a proprietary ROLAP engine.
Technologies: DevExpress, HTML, OLAP, MDX, MySQL, Microsoft SQL Server, VB, C#, .NET

IT Consultant

2002 - 2009
Freelance Work
  • Designed and implemented a production management system powered by bar code based data collection that enabled real-time insights into the production progress.
  • Designed a PocketPC based app that allowed plant managers to monitor production progress in real-time from anywhere within the facility.
  • Built a school management application that helped manage courses, classrooms, scheduling, billing, and reporting.
  • Implemented and customized a groupware system for the knowledge base, internal scheduling, articles, and polling.
Technologies: Citrix, OLAP, MDX, Firebase, MySQL, Oracle, Microsoft SQL Server, VB.NET, Visual Basic

Medical Transportation Intelligence Center

A business intelligence system for a medical transportation company that integrated otherwise isolated billing and dispatch systems to allow for simplified reporting, analysis, and effective business management.


FLIQ is a movie intelligence platform powered by AI technology. It gives unprecedented access to rich, interactive movie analytics.
1998 - 2004

Master's Degree in Industrial Engineering and Management

Slovak Technical University - Bratislava, Slovakia, EU


MCITP SQL Server Database Administration



MCITP SQL Server Business Intelligence



MCITP SQL Server Database Development



Flask-RESTful, Node.js, NumPy, Natural Language Toolkit (NLTK), Windows Forms (WinForms)


Microsoft Power BI, Microsoft Visual Studio, Talend ETL, Visual Studio, Spyder, PyCharm, Tableau, Mongoose


SQL, JavaScript, C#, Python, HTML, Java, VB, MDX, VB.NET, CSS, R, Visual Basic, ML Programming Language, Markdown, AutoIt


Microsoft SQL Server, SQL Server Management Studio (SSMS), PostgreSQL, MySQL, Data Pipelines, NoSQL, SQL Server 2016, Redshift, Pervasive PSQL, MongoDB, SQL Server Integration Services (SSIS)


Database Design, ETL, REST, OLAP, Agile Software Development, DevOps


.NET, Angular, ASP.NET Web API, Flask, Windows PowerShell, AngularJS


Docker, Talend, Oracle, Firebase, Citrix, H20, RStudio, Azure, Amazon Web Services (AWS), Visual Studio Code (VS Code)


Data Warehousing, Data Warehouse Design, Software Development, Data Analytics, Data Modeling, Data Engineering, Predictive Analytics, Full-stack, Machine Learning, APIs, Natural Language Processing (NLP), Virtualization, Data Mining, Lean Startups, DevExpress, Angular Bootstrap, Generative Pre-trained Transformers (GPT)

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