Robust quality assurance (QA) is critical to the success of large core banking transformations, where banks often face tough trade-offs between speed and system reliability. A well-planned, integrated QA approach reduces cutover risk in these complex, high-stakes programs. QA must go beyond basic user acceptance testing to include factory testing, system integration, UAT, regression, performance and security testing, ensuring coverage reflects real end-user experience.

Timing and sequencing are vital: testing must precede training, and training must precede go-live. Typically, 3–4 rounds of UAT using migrated, production-like data are recommended. Ownership should remain with the bank, while execution can be supported by external specialists to improve efficiency.

Effective QA balances depth, duration and exit criteria. Large programs often require tens of thousands of test cases, stringent defect thresholds and clear acceptance metrics. Investing deeply in QA upfront ensures smoother cutover, stronger user confidence and long-term system stability.