McCully Du Toit

Senior SQL Developer and Payment Integration Specialist with more than 25 years of experience designing, developing and supporting enterprise financial systems. I specialise in Microsoft SQL Server, Sybase ASE, T-SQL/Transact-SQL, payment processing, banking integrations, database architecture, legacy platform migration and solving complex business problems. Throughout my career I have worked on business-critical systems supporting payments, reconciliations, financial reporting and operational processing where reliability and performance are essential.

My strength lies in understanding complex SQL Server environments, investigating root causes, modernising legacy systems and delivering practical, maintainable solutions that reduce business risk. After years in technical leadership and executive roles, I am intentionally returning to hands-on engineering. I am seeking remote consulting or contract opportunities with international clients where I can deliver high-quality SQL Server and Sybase ASE solutions, payment integrations and financial systems that create measurable business value.

Self-taught since 1979, I've continually picked up new platforms as the work demanded — COBOL, PowerBuilder, Sybase ASE, SmartStream Financials, SQL Server — and most recently applied AI-assisted development to accelerate delivery on a large-scale data engineering project.

Senior SQL Developer → Team Lead → COO / CFO (Concurrent Technical Ownership) - Confidential Client

(1999-12 - 2024-12)

Senior SQL Developer for a medical aid administration system, progressively promoted through Team Lead and into COO and CFO roles at this 25-employee company while retaining direct, hands-on ownership of the core financial database throughout — development remained a primary focus even at executive level, due to deep system expertise no successor could immediately replace.

• Part of the team that designed and developed a new in-house medical aid administration system using PowerBuilder (PowerBuilder served as the presentation tier), Sybase ASE for the DBMS and SmartStream Financials as the financial system.
• Wrote and maintained the system's core business logic directly in Sybase ASE using Transact-SQL — stored procedures, triggers, views and functions — for over a decade, in an architecture where the database layer carried all business rules
• Owned query and performance tuning, indexing/partitioning strategy, and execution plan analysis across a database of 1,000+ tables and 8,000+ stored procedures, where all business logic resided at the data layer
• Engineered high-throughput transaction processing, posting 50,000 daily records into SmartStream Financials within a constrained overnight batch window to meet near-real-time processing requirements
• Delivered full SDLC ownership (analyse, design, develop, test, implement, support) for financial process changes, including ongoing production support and troubleshooting for a mission-critical, high-volume transactional system
• Designed and built financial interfaces (receivables and payables) to and from SmartStream Financials, a third-party enterprise financial package
• Developed bidirectional bank interfaces to transmit payment files and ingest reconciliation files, automatically updating the administration system
• Built integrations to external client financial packages (Sage, Accpac) to support downstream accounting requirements for medical aid scheme clients
• Led the migration of the administration system's 1,000+ tables and 8,000+ stored procedures from Sybase ASE (Transact-SQL) to Microsoft SQL Server (T-SQL) — covering syntax and data-type conversion, stored procedure and trigger rewrites, data migration, regression testing and cutover planning — with zero data loss and no disruption to live processing
• Identified SmartStream's licensing cost — which added roughly R1 million (US$50,000) to every tender submission, pricing the company out of client budgets — as a critical business risk, and led the end-to-end design and development of an in-house financials module (receivables and payables) to fully replace it
• Built automated receivables collection-run processing to generate supplier collections directly into the in-house system. Auto allocation/rejection of funds processing was a key feature development in receivables module
• Built automated payables payment-run processing to generate supplier payments directly from the in-house system
• Preserved and extended all existing bank and third-party financial-package interfaces during the migration, ensuring zero disruption to reconciliation and payment workflows
• Executed a full historical data migration from SmartStream to the in-house system, encompassing all invoices, journals and related financial records, while maintaining complete data integrity, giving clients the ability to view and modify legacy data
• Directly restored tender competitiveness by eliminating third-party licensing costs from the company's cost base
• Progressed into a Team Lead role overseeing the development team responsible for the core administration system, coordinating priorities across database development, financial interfacing, and support work
• Mentored junior and mid-level developers on T-SQL standards, code review practices, and the system's business-logic-in-database architecture
• Acted as primary technical point of contact for client stakeholders, gathering requirements, advising on solution design, and documenting new processes
• Bridged business and technical teams during the SmartStream-to-in-house transition, translating financial operations requirements into database architecture and process design

Junior Programmer / Consultant - Q Data

(1991-01 - 1999-11)

Medical Aid Administration Systems

• Maintained and enhanced an in-house administration system for a medical aid administration client as part of a consulting engagement
• Built foundational expertise in medical aid administration data structures and financial processing that directly informed later senior and executive-level work
• Progressed from junior programmer to consultant, taking on increasing client-facing responsibility

Computer Operator → Junior Programmer - Infoplan

(1979-01 - 1990-12)

• Began my career as a computer operator before teaching myself COBOL programming through independent study. Progressed into a junior programmer role through demonstrated technical ability, establishing the foundation for a 45-year career spanning enterprise financial systems, SQL Server development, systems integration, technical leadership and executive management.

Matric