Tandi Dell, Developer in Johannesburg, Gauteng, South Africa
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Tandi Dell

Verified Expert  in Engineering

Data Engineer and Developer

Johannesburg, Gauteng, South Africa
Toptal Member Since
December 12, 2022

Tandi is a seasoned developer who has been solving business problems for 25+ years. She started her career as a software engineer and transitioned to freelancing as a data specialist more than 15 years ago. During this time, she has designed and developed relational databases, data warehouses, data visualizations, and business intelligence solutions. Tandi has also performed data migrations and integrations, created ETL pipelines, and built enhanced back-end functionality for existing systems.


Altron Karabina
Microsoft SQL Server, T-SQL (Transact-SQL), Business Intelligence (BI)...
Microsoft SQL Server, T-SQL (Transact-SQL), ETL...
Altron Karabina
Microsoft SQL Server, T-SQL (Transact-SQL), SQL Performance...




Preferred Environment

T-SQL (Transact-SQL), Microsoft SQL Server, SQL Server Reporting Services (SSRS), Microsoft Power BI, Data Modeling, Business Intelligence (BI), Data Analysis, Data Warehousing, SQL Server Integration Services (SSIS), Data

The most amazing...

...product I've co-owned and developed was a database monitoring tool that became known as Diagnostic Manager when NetIQ acquired it in Houston, Texas.

Work Experience


2014 - PRESENT
Altron Karabina
  • Developed SQL Server staging, operational data store (ODS), and data warehouse databases in BI solutions.
  • Designed and developed ETL processes and pipelines to populate the staging, ODS, and data warehouse databases. Source and target data included Azure Data Lake storage, CRM, CSV and Excel files, SQL tables, and more.
  • Architected and built interfaces between systems. This included the creation of audit logs and error handling as needed to meet the system's requirements.
  • Maintained and supported Power BI dashboards, SSRS reports, SSAS cubes, tabular models, and automated interfaces between systems.
  • Conducted data analysis and profiling to assess data quality and to identify the necessary source-to-target mappings and transformations needed to meet the business requirements.
  • Facilitated requirements gathering workshops and interviews with business users while documenting the identified business rules and requirements.
  • Implemented relational data modeling to design operational data stores.
  • Performed dimensional data modeling to generate the bus matrix for the project, following the Kimball methodology. The developers used the bus matrix to create conformed dimensions and fact tables in the data warehouse.
  • Analyzed legacy systems and environments to prepare them for upgrading or decommissioning.
Technologies: Microsoft SQL Server, T-SQL (Transact-SQL), Business Intelligence (BI), Data Warehousing, Data Integration, SQL Server Integration Services (SSIS), SQL Server Reporting Services (SSRS), Microsoft Power BI, Azure, ETL, Data Modeling, Data Profiling, Data Warehouse Design, Agile Sprints, Waterfall Methodology, SQL Server BI, Reporting, Technical Design, DAX, MDX, SQL Server Analysis Services (SSAS), Requirements Analysis, Data Analysis, Data Visualization, SQL, Microsoft Excel, Data, Data Cleaning, Data Cleansing, Data Analytics


2008 - 2013
  • Engineered processes and reports to verify the integrity of the data on the clients' BI platform.
  • Developed a master data solution with interfaces in an SAP environment for a retail chain.
  • Built reports and dashboards to enable the Master Data Team and Data Stewards to identify and consolidate duplicate products across different retail chains to obtain a golden record for each product.
  • Created automated data feeds from systems on multiple disparate platforms for an SAP data migration project.
Technologies: Microsoft SQL Server, T-SQL (Transact-SQL), ETL, SQL Server Integration Services (SSIS), SQL Server Reporting Services (SSRS), Data Migration, Master Data, Data Integration, Reporting, Data Analysis, SQL, Data, Data Cleaning, Data Cleansing, Data Analytics


2007 - 2010
Altron Karabina
  • Performed troubleshooting and stabilization on an existing business-critical SQL BI System.
  • Provided user support and maintenance on an existing business intelligence solution.
  • Created ETL modules for multiple sub-systems used in the manufacturing environment.
Technologies: Microsoft SQL Server, T-SQL (Transact-SQL), SQL Performance, SQL Server Reporting Services (SSRS), ETL, Business Intelligence (BI), Data Warehousing, SQL Server Integration Services (SSIS), SQL Server BI, Reporting, Data Analysis, Data Modeling, Requirements Analysis, SQL Server Analysis Services (SSAS), Technical Design, SQL, Data, Data Cleaning, Data Cleansing


2006 - 2007
  • Assessed the client's existing reporting solution and proposed improvements that offered a more flexible and extensible solution that could carry the company into the future.
  • Developed a reporting and BI solution for a cellular provider.
  • Developed ETL processes to load data from the ERP system to an operational data store.
Technologies: Microsoft SQL Server, T-SQL (Transact-SQL), Business Intelligence (BI), ETL, SQL Server Integration Services (SSIS), Reporting


2005 - 2006
IDS Consultants
  • Created the ETL processes for a business intelligence project.
  • Developed exception reports used in fraud detection.
  • Built vetting processes for red-flag or green-light applicants.
Technologies: Microsoft SQL Server, SQL Server Integration Services (SSIS), SQL Server Reporting Services (SSRS), T-SQL (Transact-SQL), ETL, Reporting, SQL Server BI, Data Analysis, Data Modeling, SQL

Business Analyst and Software Development Manager

2003 - 2005
  • Developed an HR reporting module over the existing payroll system.
  • Provided technical support to the salaries department for the payroll system.
  • Acted as the technical consultant on strategic projects within the company.
  • Investigated technologies and products that could add value and provide a competitive advantage for the company.
  • Gathered and documented user requirements around a talent acquisition system.
  • Managed the development of the talent acquisition system.
  • Built a Visual Basic.NET (VB.NET) module for a call center application.
Technologies: VB.NET, T-SQL (Transact-SQL), RPG, Microsoft SQL Server, Requirements Analysis


2003 - 2003
Freeme Wildlife Rehabilitation Centre
  • Built an admittance system to keep track of all the animals that came to the center.
  • Developed reporting over the system to show success rates, releases, injuries, diseases, etc.
  • Collected and transported injured animals and food donations.
Technologies: Microsoft Access, Software Development, Reporting

Software Engineer

2002 - 2003
  • Developed and maintained a SQL Server monitoring system written in VB.NET.
  • Provided skills and knowledge transfer to the rest of the SQL Server product team on analyzing and correcting common customer SQL Server problems.
  • Attended to customer support issues that could not be dealt with by the first and second-line customer support team.
Technologies: Microsoft SQL Server, T-SQL (Transact-SQL), Software Development, SQL Performance, VB.NET, Waterfall Methodology, SQL

Senior Software Developer

1999 - 2002
Subquery Innovations
  • Developed and maintained a SQL Server monitoring system written in Visual Basic 6 (VB6).
  • Assisted with product marketing and sales at international conferences.
  • Maintained the company website, including HTML content updates, uploaded new releases, and upgraded software products using FTP utilities.
  • Handled telephonic and email customer support issues.
Technologies: Microsoft SQL Server, T-SQL (Transact-SQL), Software Development, SQL Performance, Visual Basic, SQL

Software Developer

1996 - 1999
  • Developed and maintained modules of an ERP system written in VB6.
  • Created a Data Warehouse component for an ERP application.
  • Built an executive information reporting module for the ERP application.
  • Assisted with user training, including compiling the training material and presenting the training topics.
Technologies: Microsoft SQL Server, T-SQL (Transact-SQL), Visual Basic, Software Development, SQL Performance, Reporting, SQL


1990 - 1996
Investec Group
  • Built an electronic system to automate the banks' monthly payroll process, which resulted in substantial time and cost savings.
  • Set up data cleansing and staging routines to automate data transfer between disparate systems and platforms such as Sybase and the AS400.
  • Developed and maintained systems written in RPG and LANSA, which integrated with the primary banking system.
  • Acted as a relationship manager between IT and specific business units within the bank. The goal was to keep the business unit informed of any new IT strategies and to assist the business unit with obtaining IT solutions to any business challenges.
  • Coordinated development requests and allocated appropriate developers to the tasks using MS Project.
Technologies: AS400, RPG, LANSA, Software Development

Investment Fund Reporting

Created an automated reporting solution related to investment portfolios. Developed multiple sets of reports over a multi-dimensional cube and a data warehouse. Each set of reports needed to be branded dynamically (logos, colors, fonts, etc.) so that the same report could be used for different clients.

The solution included the following:
• Monthly fund performance reports generated in pdf format.
• Consolidated quarterly reports that leveraged off and incorporated the monthly reports by dynamically changing certain of their properties, also generated in PDF format.
• Automatically updating embedded charts and images in PowerPoint presentations using SSRS.
• Downloadable paginated reports for internal use within the company and for sharing with partners in a combination of Excel and PDF reports.

I was responsible for liaising with the business to determine the exact requirements for each new report set, developing the MDX and T-SQL queries used by the reports, and developing the reports themselves.
The automated reporting solution replaced a labor-intensive manual process and saved the company thousands of person-hours per month.

Finance System Integration

The client's ERP system was missing key functionality. In addition, the existing interface into their finance system was essentially manual, and the process to overcome the limitations was time-intensive, prone to errors, and resulted in high-level, aggregated transactions in the finance system.

During this project, I addressed the limitations by delivering the following:
• Developed a SQL module that delivered reinsurance functionality absent in the ERP system.
• Created automated integration between the ERP system, the reinsurance module, and the finance system. Business users could also execute the interface on-demand through a Power Flow App component.
• Created an operational data store used for reporting.
• Supplemented existing financial reports with additional SSRS paginated reports that could be downloaded for further analysis.

CRM Data Integration

Created a set of SQL Integration Services (SSIS) packages using the KingswaySoft components to load data into Dynamics CRM. It was necessary to have full audit capability to identify such things as the number of source records, destination records, count of new records loaded, updated records, error records, and package execution time.

During this project, I worked closely with the team of CRM developers to ensure that the pipeline I developed delivered the expected data within the required timeframes.

The audit logs that were developed exceeded the expectations of the client. They were delighted with the fact that they could easily build their own reports on the data to address any queries raised by auditors.

Report Usage Analysis

Analysis of legacy reporting platforms in preparation for decommissioning the environments in favor of an Azure Databricks reporting and analytics environment. In this project, I was responsible for the following:

• Conducting workshops with business users to understand their report usage and critical report needs.
• Facilitating workshops with technical resources to understand the legacy environments and the proposed new reporting environment.
• Creating SQL scripts over the SSRS metadata to identify recently used SSRS reports and the databases and tables referenced by them.
• Building SQL scripts over an Azure Databricks database to identify usage stats on Power BI reports in both Premium and Pro capacity.
• Developing SQL scripts to identify cross-server and cross-database queries.
1992 - 1996

Bachelor's Degree in Mathematics and Computer Science

University of South Africa (UNISA) - Pretoria, South Africa


AZ-900: Microsoft Azure Fundamentals



SQL Server BI, Microsoft Power BI, Microsoft Access, Microsoft Excel


T-SQL (Transact-SQL), SQL, RPG, Visual Basic, VB.NET, MDX


ETL, Business Intelligence (BI), Requirements Analysis


Microsoft SQL Server, SQL Server Integration Services (SSIS), SQL Server Reporting Services (SSRS), Data Integration, SQL Performance, SQL Server Analysis Services (SSAS)




Data Warehousing, Reporting, Data Migration, Data, Data Cleaning, Data Cleansing, Data Analytics, Data Analysis, Data Modeling, Data Profiling, Data Warehouse Design, Technical Design, Data Visualization, Software Development, AS400, LANSA, Master Data, Agile Sprints, Waterfall Methodology, DAX

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