Tandi Dell
Verified Expert in Engineering
Data Engineer and Developer
Johannesburg, Gauteng, South Africa
Toptal member since December 12, 2022
Tandi is a seasoned analyst and 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 many data warehouses, business intelligence solutions, and informative data visualizations. Tandi has also performed data migrations and integrations, created ETL pipelines, and enhanced back-end functionality for existing systems.
Portfolio
Experience
- T-SQL (Transact-SQL) - 20 years
- Microsoft SQL Server - 20 years
- Business Intelligence (BI) - 15 years
- Data Warehousing - 15 years
- Data Visualization - 10 years
- Dimensional Modeling - 10 years
- Requirements Analysis - 8 years
- Microsoft Power BI - 4 years
Availability
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), Dimensional Modeling
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
Consultant
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.
Consultant
EnterpriseWorx
- 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.
Consultant
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.
Consultant
Entelect
- 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.
Consultant
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.
Business Analyst and Software Development Manager
Smollan
- 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.
Volunteer
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.
Software Engineer
NetIQ
- 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.
Senior Software Developer
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.
Software Developer
Qmuzik
- 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.
Developer
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.
Experience
Data Visualization: Financial Audit Dashboard and Reports
Investment Fund Reporting
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
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
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
• 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.
Education
Bachelor's Degree in Mathematics and Computer Science
University of South Africa (UNISA) - Pretoria, South Africa
Certifications
Microsoft Fabric Analytics Engineer Associate
Microsoft
Power BI Data Analyst Associate
Microsoft
AZ-900: Microsoft Azure Fundamentals
Microsoft
Skills
Libraries/APIs
PySpark
Tools
SQL Server BI, Microsoft Power BI, Microsoft Access, Microsoft Excel, Power Query
Languages
T-SQL (Transact-SQL), SQL, RPG, Visual Basic, VB.NET, MDX, Power Query M
Paradigms
ETL, Business Intelligence (BI), Dimensional Modeling, Requirements Analysis
Storage
Microsoft SQL Server, SQL Server Integration Services (SSIS), SQL Server Reporting Services (SSRS), Data Integration, SQL Performance, SQL Server Analysis Services (SSAS)
Platforms
Azure, Fabric Lakehouse, Microsoft Fabric
Other
Data Analysis, Data Warehousing, Reporting, Data Migration, Data Warehouse Design, Data, Data Cleaning, Data Cleansing, Data Analytics, Data Modeling, Data Profiling, Technical Design, DAX, Data Visualization, Software Development, AS400, LANSA, Master Data, Agile Sprints, Waterfall Methodology, Modeling, Star Schema, Performance Testing, Slowly Changing Dimensions (SCD), User Requirements, Data Engineering, Azure Data Factory (ADF), Delta Lake, Delta Tables, Reports
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