Khalil Achach, Developer in Elkton, MD, United States
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Khalil Achach

Verified Expert  in Engineering

Data Engineer and Developer

Elkton, MD, United States
Toptal Member Since
November 7, 2023

Khalil is a senior data engineer with extensive experience in data extraction, analysis, and reporting. Holding a bachelor of science degree in computer science, he is proficient in a wide range of programming languages and has successfully built numerous applications throughout his career. Over the last 15 years, Khalil has worked at Comcast, honing his expertise in various data engineering technologies such as SQL, SQL/SSIS, Excel VBA, Databricks, Scala, and PySpark.


Microsoft SQL Server, SQL Server Integration Services (SSIS)...
Bank of America
Excel VBA, Microsoft Access, Microsoft Excel, Windows, Microsoft Word...
Windows XP, Windows Server 2000, SAP R/3, Visual Basic 6 (VB6), VBScript...




Preferred Environment

Microsoft SQL Server, SQL Server Integration Services (SSIS), Excel VBA, Databricks, Scala, PySpark, Visual Basic 6 (VB6), Visual Basic .NET (VB.NET)

The most amazing...

...thing I've done was move dozens of SSIS packages and SQL store procedures to Databricks using Python, Scala, and SQL after two months of learning Databricks.

Work Experience

Senior Data Engineer

2007 - 2023
  • Undertook the migration of big data pipelines from on-premises platforms using T-SQL, SQL Server Integration Services (SSIS), and Apache Hive to cloud-based platforms, especially AWS and Databricks utilizing Scala and SQL.
  • Designed ETL solutions for seamless data integration. These solutions were instrumental in cleaning and organizing raw data and preparing it for storage, data analytics, and machine learning (ML).
  • Worked closely with customers and acted as a liaison between customers and the senior leadership team (SLT). I also took responsibility for building and maintaining the daily, weekly, and monthly dashboards for SLT analysis.
  • Automated the data validation process for generating and distributing reports via email, Slack, or Microsoft Teams. Used diverse tools for the automation process, including SQL Server Integration Services (SSIS), SQL, Databricks, and Scala.
  • Designed, developed, and deployed complex reports using Microsoft Visual Basic Script (VBScript) and Excel Visual Basic Application (VBA).
  • Produced specifications documentation for daily, weekly, and monthly reports using Microsoft Visio.
Technologies: Microsoft SQL Server, SQL Server Integration Services (SSIS), T-SQL (Transact-SQL), VBScript, Excel VBA, Databricks, Scala, PySpark, SQL, ETL, Data Engineering, Python, Data Pipelines, Hadoop, Amazon Web Services (AWS), Big Data, Spark, Amazon S3 (AWS S3), ETL Development, ETL Implementation & Design, ETL Testing, Data Visualization, Databases, Snowflake, Data Analytics, Data Analysis, Database Migration, Visual Basic .NET (VB.NET), Unix Shell Scripting, SQL Server Reporting Services (SSRS), Apache Hive, Tableau, ETL Tools, Microsoft Data Transformation Services (now SSIS), SSIS Custom Components, Visual Studio, Windows, Microsoft Word, Visual Basic for Applications (VBA), SQL Stored Procedures, Performance Tuning, Visual Basic, Excel Expert, Power Query, JSON REST APIs, C#, Excel Macros, Microsoft Outlook

Software Engineer

2006 - 2006
Bank of America
  • Contributed to the organization and implementation of a conversion project involving the migration of all correspondence containing legacy MBNA text to Bank of America.
  • Created reporting tools using Microsoft Excel, Microsoft Access, and OpenText HostExplorer to give upper management an overview of LVIS Letter Group's workflow.
  • Built queries in Microsoft Access and created charts in Microsoft Excel to showcase the annual rollup data to upper management.
  • Created and updated customer correspondence to become available across the United States, Canada, and Puerto Rico using Document Library Services (DLS) software within DDM Edit, Ver.6.4, for Windows by Document Sciences Corporation.
Technologies: Excel VBA, Microsoft Access, Microsoft Excel, Windows, Microsoft Word, Visual Basic for Applications (VBA), Excel Expert


2005 - 2006
  • Developed an application with Visual Basic 6 using a Microsoft Access database and Microsoft Excel report to track real-time results of mobile automation for 13,000 users.
  • Created multiple Microsoft Excel macros and a Visual Basic for Applications (VBA) codebase using forms to expedite managers' access to the results of mobile automation projects.
  • Collaborated with customer service to resolve customers' technical issues using the ManageNow ticketing software.
  • Helped troubleshoot errors that could arise from software and hardware upgrades in the mobile automation projects.
Technologies: Windows XP, Windows Server 2000, SAP R/3, Visual Basic 6 (VB6), VBScript, Microsoft Access, Microsoft Excel, ABAP, Informatica, Windows, Microsoft Word, MacOS, Excel Expert

System Analyst | Programmer

2000 - 2001
  • Supported Andesa's system and production, which involved performing upgrades, conducting analysis, developing programs to meet business requirements, identifying and fixing errors, and implementing unit testing.
  • Maintained desktop applications written in Visual Basic V4/5 and Microsoft Access/Visual Basic for Applications (VBA). I also converted some of these applications to ensure compliance with Windows 2000, which involved testing and certification.
  • Developed a Microsoft Access application for an insurance company. The application creates a deposit system and allows users to search and print reports based on various criteria such as cash, check, customer, date, and amount.
  • Served as a SCO UNIX Open Server 5.0.4 administrator, performing backups and data retrievals, setting up user accounts, and writing and using shell scripts for business-related functions.
Technologies: Unix Shell Scripting, Pascal, Microsoft Access, Microsoft Excel, Unix, Microsoft Word

Capacity Dashboard Report

Over the last 15 years, I have developed various Excel programs using Visual Basic for Applications (VBA) and leveraging my expertise in Microsoft Excel reports.

One of my latest projects involved creating a capacity dashboard report to collect approximately 3,000 daily CSV files, each with a size of around 2KB, and extract relevant data from them. The collected data was then combined in a monthly Microsoft Excel file. This process led to significant savings in time and human resources, with the time to push the dashboard to upper management being reduced from over 2 weeks to 2 hours.

COVID-19 Capacity Management

The pandemic prompted significant changes in user behavior, and a comprehensive analysis of the new scenario was needed. I played a crucial role in supporting COVID-19 capacity management by conducting an in-depth analysis of peak traffic shifts from night to day and vice versa across various sites and regions.

By analyzing and interpreting this data, I provided valuable insights that informed the senior leadership team and contributed to crucial decision-making processes. The daily reports I generated became an essential tool, saving the company valuable time and resources.

Cloud Migration Project

A cloud migration project in which I was the liaison between customers and the senior leadership team, providing all the reports in SQL Server views, Microsoft Excel files, and Tableau.

Because of my role in the project, I spearheaded the whole process comprising two steps. The first step involved using an API to collect raw data and then store it in an Amazon S3 bucket or a cloud database. The second step targeted the conversion of the SQL Server store procedure, and SQL Server Integration Services (SSIS) packages to Databricks using Scala, SQL, and PySpark. This new technology led to significant savings in time and money, with the monthly report that used to take 3 days to be ready then taking only around 4 hours.

Database Migration Specialist at PointClickCare

The objective was to contribute to PointClickCare's mission of transforming healthcare through technology and collaboration by ensuring the successful migration of databases in accordance with company standards.

• Database migration: Executed the migration of databases, adhering strictly to PointClickCare's criteria to ensure data integrity and system compatibility.
• Automation: Developed and implemented automated jobs to streamline the migration process, enhancing efficiency and reducing manual intervention.
• Error debugging: Identified and resolved database errors, including primary key and foreign key constraints, to maintain relational database integrity and prevent data anomalies.
• Collaboration: Worked closely with cross-functional teams to ensure seamless integration of new systems and databases, supporting the company's collaborative approach to technological transformation.
1985 - 1986

Bachelor of Science Degree in Computer Science

University of Montpellier - Montpelier, France

1983 - 1985

Associate's Degree in Computer Science

Institute of Seraing - Seraing, Belgium




Microsoft Excel, Microsoft Word, Microsoft Outlook, Turbo Pascal, Visual Studio, Power Query, Tableau, Microsoft Access, Excel 2010


Excel VBA, T-SQL (Transact-SQL), SQL, Visual Basic for Applications (VBA), VBScript, Visual Basic 6 (VB6), Visual Basic .NET (VB.NET), Visual Basic, Scala, COBOL, Assembly, Python, Snowflake, ABAP, Pascal, C#


Windows, Databricks, Amazon Web Services (AWS), Windows XP, Windows Server 2000, Unix, MacOS


ETL, ETL Implementation & Design


Microsoft SQL Server, SQL Server Integration Services (SSIS), SQL Stored Procedures, Databases, SQL Server Reporting Services (SSRS), Apache Hive, Data Pipelines, Amazon S3 (AWS S3), Database Migration, SQL Server 2016


Hadoop, Spark


Microsoft Data Transformation Services (now SSIS), SSIS Custom Components, Excel Expert, Excel Macros, Analysis, Software Development, Computer Skills, Data Engineering, ETL Development, ETL Testing, Data Visualization, Data Analytics, Data Analysis, Performance Tuning, Unix Shell Scripting, Big Data, SAP R/3, Informatica, ETL Tools, APIs, JSON REST APIs, Data Migration

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