Thabo Mailula | Freelancer Resume

Thabo Mailula Portfolio: https://ncedox82.wixsite.com/insights-by-thabo GitHub: https://github.com/ncedox Locations: Gauteng and Cape Town Professional Summary Data Analyst experienced in designing scalable cloud ETL pipelines and high-performance Power BI models for large transactional environments processing 21M+ daily records. Built Azure-based data architecture using Data Lake, Parquet, and Synapse Serverless to eliminate system crashes and reduce refresh times. Strong in Python, SQL, star-schema modeling, and performance optimization. Focused on delivering reliable, executive-ready analytics.. CORE SKILLS Data Engineering & Cloud ● Python (Pandas, chunked processing, ETL automation) ● Azure Data Lake Storage Gen2 ● Azure Synapse Serverless SQL ● Parquet optimization & partitioning ● File-triggered automation (watchdog) Analytics & BI ● Power BI (Star Schema, DAX, Time Intelligence) ● KPI framework design ● Revenue, growth, and trend analysis ● Import mode optimization & reduced cardinality modeling Databases ● SQL Server, MySQL, PostgreSQL ● CTEs, aggregations, views, query tuning PROFESSIONAL EXPERIENCE Data Analyst Professional Experience Data Analyst 2023-Present Afsol Pty Ltd / Tanzanite – Cape Town ● Designed and implemented an end-to-end cloud ETL and reporting architecture to process 21M+ daily transactions using Python (2–4 years) and SQL Server (2–4 years). ● Replaced unstable local MySQL processing with a scalable Azure-based solution, improving reliability and performance. ● Built automated Python ETL pipeline (2–4 years) with chunked processing, reducing RAM usage and preventing system overload. ● Converted large CSV datasets into optimized Parquet format (Big Data – 2–4 years) for storage efficiency and faster queries. ● Implemented raw and curated layers in Azure Data Lake, with date-based partitioning for scalable performance. ● Configured Azure Synapse Serverless SQL (2–4 years) to query Parquet files without infrastructure management. ● Reduced Power BI refresh times (2–4 years) by loading aggregated curated datasets instead of raw 21M+ row tables. ● Designed a star-schema model in Power BI with proper data types and reduced cardinality to optimize reporting. ● Developed DAX measures (2–4 years) for Total Revenue, YTD, MoM/YoY Growth %, and Average Transaction Value. ● Delivered stable scheduled refreshes and executive-ready dashboards (Data Visualisation – 2–4 years) supporting operational and financial decision-making. ● Impact ● Eliminated RAM overload and database crashes. ● Improved reporting reliability and refresh performance. ● Built scalable architecture to support continuous daily data growth. Selected Analytics Projects Operational & Performance Analytics – Maji Ndogo Water Services SQL (1–3 years), Power BI (1–3 years), Data Visualisation (1–3 years) ● Integrated multi-table operational datasets using SQL best practices, ensuring clean, accurate reporting. ● Analyzed service coverage, queue times, and hourly performance patterns to identify operational bottlenecks. ● Built KPI dashboards in Power BI to support infrastructure planning and decision-making. Sales Performance Dashboard Power BI (1–3 years), Data Analysis (1–3 years) ● Developed interactive dashboards tracking revenue, regional performance, and product trends. ● Enabled drill-down analysis for management, helping improve sales strategy and performance monitoring. Customer & Marketing Insights Dashboard Power BI (1–3 years), Data Analysis (1–3 years) ● Analyzed retention cohorts and promotion effectiveness to uncover actionable insights. ● Built segmentation views highlighting customer behavior patterns and areas for targeted campaigns. PREVIOUS EXPERIENCE Previous Experience- Senior Financial Planner ABSA Bank – Pretoria ● Managed 100+ client portfolios using structured financial analysis. ● Improved average portfolio performance by approximately 12%. ● Presented performance insights to senior stakeholders. Financial Planner 2014 - 2015 ABSA Bank – Pretoria ● Built quantitative financial plans aligned to long-term growth objectives. ● Delivered data-backed recommendations to clients and management. Business Owner / Operations Manager Holding Pillar Pty Ltd – Pretoria ● Managed e-commerce operations and performance analytics. ● Used sales and marketing data to improve operational efficiency. Business Owner / Operations Manager- Holding Pillar Pty Ltd – Pretoria 1year - 7 years ● Managed ecommerce operations and performance analytics. ● Used sales and marketing data to improve operational efficiency. EDUCATION BSc Mathematics & Operations Research University of South Africa Data Science (In Progress) ALX Africa Business Intelligence & Data Analytics Corporate Finance Institute National Certificate in Data Metrics University of South Africa Financial Planning NQF 5 Milpark Education