Core Banking Defects Are Invisible Until They're Not.
The three failure modes that derail core banking programmes — and how independent QA prevents them.
Data Migration Errors Surface Post-Launch
Account balances, interest calculations, and transaction histories migrated from legacy systems carry silent data quality issues. These defects don't appear until reconciliation cycles post-launch — when correction is expensive and customer impact is unavoidable. Systematic data migration validation before cutover is non-negotiable.
Integration Gaps With Downstream Systems
Core banking systems connect to payment rails, statement generation, card systems, internet banking, and regulatory reporting. Integration defects between the new core and downstream systems often only emerge when live transaction volumes expose edge cases that test data never covered. Independent end-to-end integration testing is essential.
Regulatory Requirements Not Systematically Verified
RBNZ compliance, AML/CFT obligations, and privacy requirements create a testing obligation that delivery teams — focused on functional delivery — routinely under-test. Independent regulatory coverage verification before go-live ensures the programme doesn't create a compliance risk alongside a technology one.
How Resync Approaches Core Banking QA
Core banking testing is not standard functional QA with banking-themed test cases. It requires deep knowledge of banking product logic — how interest accrues across product types, how GL journals behave across closing periods, how payment instructions flow from instruction to settlement. Resync's core banking specialists bring that domain knowledge alongside structured QA discipline.
Every engagement starts with a risk-based test strategy that covers the migration scope, integration landscape, and regulatory obligations specific to your programme. We validate data migration completeness and accuracy, test integration behaviour under realistic transaction volumes, and structure UAT with operations and compliance teams to ensure coverage that reflects how the system will actually be used.
Independent QA on a core banking replacement means the bank — not the SI — has an honest view of readiness before cutover day.
What We Test
Full QA coverage across migration, integration, regulatory compliance, and business readiness.
Data Migration Validation
Systematic reconciliation of account balances, transaction histories, and product configurations migrated from legacy systems. Balance-to-balance verification, exception identification, and correction tracking.
GL & Journal Testing
Validate general ledger posting logic, journal entry accuracy, period-end behaviour, and GL reconciliation across all product lines and transaction types.
Payment Rail Integration
Test SWIFT, RTGS, retail payment, and card network integration points for correctness, exception handling, and settlement accuracy under concurrent transaction load.
Regulatory Compliance Testing
Structured coverage of RBNZ reporting obligations, AML/CFT transaction monitoring, and privacy requirements — ensuring regulatory obligations are verified, not assumed.
Regression & Platform Stability
Maintain regression coverage through configuration changes, hotfix deployments, and ongoing parallel operation phases. Protect platform stability during the critical parallel-run period.
UAT Facilitation
Structure and facilitate business UAT with operations, finance, and compliance teams. Build test scenarios that reflect real customer types, product combinations, and edge cases — not just happy paths.
Independence
Independent of Every Core Banking Vendor.
Accountable Only to You.
Most QA firms on core banking programmes are affiliated with the implementation partner or the platform vendor. Their findings are filtered through a commercial relationship. Resync has no relationship with Temenos, Finzsoft, TCS BaNCS, Thought Machine, or any other core banking platform. Our assessment is honest because our only client relationship is with the bank.
Why Resync for Core Banking?
Independent. Domain-expert. Accountable.
Truly Independent
No core banking platform vendor relationship. No SI partnership. Our findings — including unfavourable readiness assessments — are delivered honestly because our only obligation is to the bank.
Banking Domain Expertise
Our core banking specialists understand product logic, GL behaviour, payment flows, and regulatory obligations — not just test methodology. Domain knowledge is what makes the difference in core banking QA.
Outcomes, Not Activities
We measure success by go-live readiness confirmed, defects caught before cutover, and reconciliation clean runs achieved — not test cases executed. Programme leadership gets the honest assessment they need.
Frequently Asked Questions
What programme directors and CIOs ask before engaging Resync for core banking quality assurance.
Q.Can Resync work alongside our implementation partner?
Yes. Resync embeds independently from the SI, providing the objective quality layer the bank needs. Our role is to verify what has been built, not validate the SI's delivery. That independence is what gives the bank's executive team and board an honest view of go-live readiness.
Q.How do you approach data migration testing for large account portfolios?
Resync uses a structured reconciliation approach: source-to-target mapping validation, balance verification at account and portfolio level, transaction history completeness checks, and product configuration comparison. For large portfolios, we implement automated reconciliation tooling that can process the full account population rather than a sample.
Q.At what programme stage should independent QA engage?
The earlier, the better. Resync can provide value at any stage, but the highest-impact engagement point is before system integration testing begins — when test strategy, data migration validation approaches, and integration test coverage can still be shaped. Engaging QA at UAT only is common, but it limits the defects that can be caught and remediated before go-live.
Q.What regulatory testing does Resync cover for NZ banks?
Resync's testing covers RBNZ reporting obligations (including capital adequacy and liquidity data flows), AML/CFT transaction monitoring and threshold rules, and NZ Privacy Act obligations for customer data handling. We don't provide legal advice, but we systematically verify that the system produces the outputs required for compliance verification.