Banking Expert
Expert guidance for banking systems, core banking platforms, regulatory compliance, and banking technology.
Core Concepts
Banking Systems
- Core banking systems (CBS)
- Account management
- Transaction processing
- Payment systems (ACH, SWIFT, SEPA)
- Loan management
- Risk management systems
Regulations
- Basel III/IV capital requirements
- Know Your Customer (KYC)
- Anti-Money Laundering (AML)
- GDPR for banking
- PSD2 (Payment Services Directive)
- Dodd-Frank Act
Key Technologies
- Real-time payment processing
- Mobile banking
- Open banking APIs
- Digital wallets
- Blockchain in banking
- AI for fraud detection
Account Management
from decimal import Decimal
from datetime import datetime
from enum import Enum
class AccountType(Enum):
CHECKING = "checking"
SAVINGS = "savings"
CREDIT = "credit"
LOAN = "loan"
class Account:
def __init__(self, account_number: str, account_type: AccountType,
customer_id: str, balance: Decimal = Decimal('0')):
self.account_number = account_number
self.type = account_type
self.customer_id = customer_id
self.balance = balance
self.status = "ACTIVE"
self.created_at = datetime.now()
def deposit(self, amount: Decimal) -> dict:
"""Deposit funds with validation"""
if amount <= 0:
raise ValueError("Amount must be positive")
self.balance += amount
return {
"transaction_id": self.generate_transaction_id(),
"type": "DEPOSIT",
"amount": amount,
"balance": self.balance,
"timestamp": datetime.now()
}
def withdraw(self, amount: Decimal) -> dict:
"""Withdraw funds with balance check"""
if amount <= 0:
raise ValueError("Amount must be positive")
if self.balance < amount:
raise ValueError("Insufficient funds")
self.balance -= amount
return {
"transaction_id": self.generate_transaction_id(),
"type": "WITHDRAWAL",
"amount": amount,
"balance": self.balance,
"timestamp": datetime.now()
}
def transfer(self, to_account: 'Account', amount: Decimal) -> dict:
"""Transfer funds between accounts"""
# Withdraw from source
withdrawal = self.withdraw(amount)
try:
# Deposit to destination
deposit = to_account.deposit(amount)
return {
"transaction_id": self.generate_transaction_id(),
"type": "TRANSFER",
"from_account": self.account_number,
"to_account": to_account.account_number,
"amount": amount,
"timestamp": datetime.now()
}
except Exception as e:
# Rollback on failure
self.deposit(amount)
raise eKYC/AML Compliance
class KYCService:
def verify_customer(self, customer_data: dict) -> dict:
"""Perform KYC verification"""
verification_results = {
"identity_verified": False,
"address_verified": False,
"sanctions_clear": False,
"pep_check_clear": False,
"risk_level": "HIGH"
}
# Identity verification
verification_results["identity_verified"] = self.verify_identity(
customer_data["id_document"]
)
# Address verification
verification_results["address_verified"] = self.verify_address(
customer_data["proof_of_address"]
)
# Sanctions screening
verification_results["sanctions_clear"] = self.screen_sanctions(
customer_data["name"],
customer_data["date_of_birth"]
)
# PEP (Politically Exposed Person) check
verification_results["pep_check_clear"] = self.check_pep(
customer_data["name"]
)
# Calculate risk level
verification_results["risk_level"] = self.calculate_risk_level(
verification_results
)
return verification_results
class AMLMonitoring:
def monitor_transaction(self, transaction: dict) -> dict:
"""Monitor transaction for suspicious activity"""
flags = []
# Large transaction
if transaction["amount"] > 10000:
flags.append("LARGE_TRANSACTION")
# Rapid succession of transactions
if self.check_velocity(transaction["account_id"]):
flags.append("HIGH_VELOCITY")
# Unusual pattern
if self.check_pattern(transaction):
flags.append("UNUSUAL_PATTERN")
# International transfer to high-risk country
if transaction.get("international") and \
self.is_high_risk_country(transaction.get("destination")):
flags.append("HIGH_RISK_COUNTRY")
if flags:
self.file_suspicious_activity_report(transaction, flags)
return {
"flagged": len(flags) > 0,
"flags": flags,
"risk_score": self.calculate_aml_risk_score(flags)
}Payment Processing
class PaymentProcessor:
def process_ach_payment(self, payment: dict) -> dict:
"""Process ACH payment"""
# Validate routing and account numbers
if not self.validate_routing_number(payment["routing_number"]):
raise ValueError("Invalid routing number")
# Create ACH file
ach_batch = self.create_ach_batch([payment])
# Submit to ACH network
submission_result = self.submit_to_ach_network(ach_batch)
return {
"payment_id": payment["id"],
"status": "PENDING",
"expected_settlement": self.calculate_settlement_date(),
"trace_number": submission_result["trace_number"]
}
def process_wire_transfer(self, wire: dict) -> dict:
"""Process SWIFT wire transfer"""
# Generate SWIFT message
swift_message = self.create_swift_mt103(wire)
# Send via SWIFT network
result = self.send_swift_message(swift_message)
return {
"wire_id": wire["id"],
"status": "SENT",
"swift_reference": result["reference"],
"fee": self.calculate_wire_fee(wire["amount"])
}Interest Calculation
class InterestCalculator:
@staticmethod
def calculate_simple_interest(principal: Decimal, rate: Decimal,
days: int) -> Decimal:
"""Calculate simple interest"""
return principal * rate * days / 365
@staticmethod
def calculate_compound_interest(principal: Decimal, annual_rate: Decimal,
years: int, compounds_per_year: int = 12) -> Decimal:
"""Calculate compound interest"""
rate_per_period = annual_rate / compounds_per_year
num_periods = years * compounds_per_year
return principal * ((1 + rate_per_period) ** num_periods - 1)
@staticmethod
def calculate_loan_payment(principal: Decimal, annual_rate: Decimal,
months: int) -> Decimal:
"""Calculate monthly loan payment"""
monthly_rate = annual_rate / 12
payment = principal * (monthly_rate * (1 + monthly_rate) ** months) / \
((1 + monthly_rate) ** months - 1)
return payment.quantize(Decimal('0.01'))Best Practices
- Implement two-factor authentication
- Use encryption for sensitive data (at rest and in transit)
- Maintain complete audit trails
- Implement real-time fraud detection
- Ensure ACID compliance for transactions
- Regular security audits and penetration testing
- Implement rate limiting on APIs
- Use tokenization for sensitive data
- Maintain disaster recovery and business continuity plans
- Regular regulatory compliance reviews
Anti-Patterns
❌ Storing sensitive data unencrypted ❌ No transaction logging/audit trail ❌ Synchronous payment processing ❌ Ignoring regulatory compliance ❌ No fraud detection mechanisms ❌ Using floats for money calculations ❌ No backup and recovery procedures
Resources
- Basel Committee: https://www.bis.org/bcbs/
- SWIFT Standards: https://www.swift.com/standards
- PSD2: https://ec.europa.eu/info/law/payment-services-psd-2
- FFIEC: https://www.ffiec.gov/