The Maker-Checker principle acts as a critical internal control mechanism. It mandates that for any transaction (especially financial or sensitive data changes), there must be at least two individuals involved: one to initiate/create (Maker) and another to verify/authorize (Checker/Authorizer). This segregation of duties minimizes the risk of internal fraud, unauthorized transactions, and human error.

While the Core Banking System handles day-to-day transactions (OLTP), the Data Warehouse stores historical data from various sources to facilitate analysis, MIS reporting, and strategic decision-making (OLAP).

Parameter files act as the rulebook for the CBS. Changes in interest rates or product features are made here without altering the source code, allowing flexibility.

EOD is a critical batch process that runs at the end of the business day to ensure all transactions are posted, accounts balanced, and system date is moved to the next working day.

The Customer Information File (CIF) or Customer ID is the unique key assigned to a customer. Multiple accounts (Savings, Loan, FD) are linked to this single CIF to provide a 360-view of the customer relationship.

Interest calculation for millions of accounts is resource-intensive. Batch processing runs this as a background job (usually at night) to avoid slowing down the system during banking hours.

A Data Warehouse acts as a central repository of integrated historical data. Data Mining uses algorithms on this warehoused data to discover hidden patterns, correlations, and insights (e.g., predicting which customers are likely to default or identifying cross-selling opportunities).

The Delivery Channel Interface allows transactions initiated at various touchpoints (ATMs, Phones) to be routed to the Core Banking System for processing and response.

This principle ensures that a teller can only access cash modules, while a loan officer accesses loan modules, preventing unauthorized access and potential fraud.

Data Centers are rated from Tier 1 to Tier 4 based on uptime and redundancy. Tier 4 is the highest standard, offering Fault Tolerance (no single point of failure), independent dual-powered cooling/power paths, and 99.995% uptime guarantee, crucial for 24x7 banking operations.

RBI allows outsourcing of non-core activities (like IT support, hardware maintenance). However, Core Management Functions , including decision-making regarding credit, policy formulation, internal audit, and compliance, cannot be outsourced as it compromises the bank's control and accountability.

RPO determines how much data the bank can afford to lose in a disaster. For example, if RPO is 15 minutes, it means backups must be done every 15 minutes, so at most 15 minutes of data is lost. Zero RPO means real-time data replication.

The API Gateway sits between the outside world (Fintech apps) and the bank's core systems. It enforces security (authentication, rate limiting), traffic management, and analytics for all incoming API requests.

UAT is crucial to ensure the software handles real-world scenarios correctly. It validates the business logic and usability from the perspective of the people who will actually use the system.

BOD is a mandatory process run before any transaction can take place. It updates the system date, checks system health, and enables transaction posting for the new day.

Big Bang involves switching the entire bank to the new system at once (usually over a weekend). It is riskier but faster than the Phased approach.