Customer 360° Data Integration Challenge

Breaking Down Data Silos Across Multiple Banking Systems

A case study on unifying customer data from disparate CRM and core banking systems for AI-driven insights

Project Overview

Customer Experience Personalization through Multi-System Data Integration

Business Objective

Create a unified 360° view of customers by integrating data from 5 disparate banking systems to enable personalized customer experiences, targeted marketing, and improved service delivery, all while reducing operational costs by 15%.

Legacy Systems

  • Retail Banking Core (Oracle-based, 15+ years old)
  • Corporate Banking Platform (SAP, 8 years old)
  • Enterprise CRM (Salesforce, 3 years old)
  • Branch Service System (Custom .NET, 10+ years old)
  • Digital Banking Platform (Cloud-native, 2 years old)

Technical Approach

Data lake architecture with entity resolution AI models to create a unified customer master record, feeding into a machine learning engine for behavior prediction and personalization.

Key Challenge

Inconsistent data definitions, duplicate customer records, conflicting information across systems, and no common identifier to reliably match customers across all five platforms.

System Integration Analysis

Understanding data structures across five legacy systems

Banking System Landscape

Legacy Systems (10+ years)
Mid-age Systems (5-10 years)
Modern Systems (<5 years)
Strong Integration
Weak/Manual Integration
No Integration

5.2M

Total customer records across all systems

3.8M

Unique customers (estimated)

27%

Duplicate rate

58%

Contact info consistency

43%

Data field compatibility

Disparate Data Models

Attribute Retail Core Corporate Banking Enterprise CRM Branch Service Digital Banking
Customer ID ACC_ID (numeric) CORP_CUSTOMER_ID (alpha) SF_ID (UUID) BRANCH_CUST_NO (numeric) user_id (UUID)
Name Format Single field (FULL_NAME) Structured (FIRST, LAST) Structured (First, Middle, Last) Structured (Title, First, Last) Single field (display_name)
Address Structured fields Free text Structured + Geocoded Structured fields JSON object
Phone Format No country code With country code Multiple formats Local format only E.164 standard
Email Storage Optional field Multiple contacts Primary + Secondary Single field Required, verified
Date Formats DD-MM-YYYY YYYY-MM-DD ISO 8601 MM/DD/YYYY Unix timestamp
Customer Type 5 segments 3 tiers 25+ personas 7 categories Behavioral clusters

Data Quality Assessment by System

Identity Resolution Challenge

Critical Impact

With no common identifier across systems, matching customers requires probabilistic models using name, address, phone, and other attributes which vary in format, structure, and completeness across systems.

# Sample customer records from different systems
# Retail Core
{
  "ACC_ID": 28471093,
  "FULL_NAME": "SARAH J THOMPSON",
  "DOB": "15-04-1978",
  "ADDRESS1": "42 MAPLE STREET",
  "ADDRESS2": "APT 301",
  "CITY": "BOSTON",
  "STATE": "MA",
  "ZIP": "02108",
  "PHONE": "6175550123"
}

# Enterprise CRM
{
  "SF_ID": "a07f200000ZKlmnAAB",
  "First_Name": "Sarah",
  "Middle_Name": "Jane",
  "Last_Name": "Thompson-Wilson",
  "Birth_Date": "1978-04-15T00:00:00.000Z",
  "Addresses": [
    {
      "Type": "Home",
      "Street": "42 Maple St, Apt 301",
      "City": "Boston",
      "State": "Massachusetts",
      "PostalCode": "02108",
      "GeoCode": "42.3601,-71.0589"
    }
  ],
  "PhoneNumbers": [
    {
      "Type": "Mobile",
      "Number": "+16175550123"
    }
  ]
}

# Digital Banking
{
  "user_id": "7b912f4e-90aa-4d3c-b667-5316fd44ac1b",
  "display_name": "Sarah Thompson",
  "birth_date": 261360000,
  "contact": {
    "address": {
      "line1": "42 Maple Street, Apt 301",
      "city": "Boston",
      "state": "MA",
      "zip": "02108",
      "country": "US"
    },
    "phone": "+16175550123",
    "email": "sarah.thompson@example.com"
  }
}

Temporal Inconsistencies

High Impact

Address and contact information updates occur at different times across systems, leading to inconsistent "current" state for customer profiles and confusing customer interactions.

Product Definitions

Medium Impact

Product definitions and categorizations vary across systems, making it challenging to create a unified view of customer relationships and cross-selling opportunities.

AI Model Performance Impact

How data quality affects customer predictions and recommendations

Model with Raw Unintegrated Data

62% Accuracy
0.67 AUROC
0.58 F1 Score

Key Issues

  • False positives for next-best-offer recommendations (42% error rate)
  • Duplicate marketing communications sent to same customer
  • Product recommendations based on partial customer profile
  • Low personalization scores from customers (NPS: 28)
  • Customer confusion from inconsistent interactions

Model with Integrated Master Data

89% Accuracy
0.91 AUROC
0.85 F1 Score

Key Improvements

  • Holistic customer understanding across all relationships
  • Consistent customer experience across all channels
  • Relevant product recommendations (conversion up 67%)
  • Higher personalization scores from customers (NPS: 72)
  • Reduced marketing waste with 34% lower contact costs

Customer Prediction Examples

Customer Scenario Unintegrated Data Prediction Integrated Data Prediction Actual Outcome
High-value retail customer with undiscovered corporate relationship 68% likely to open retirement account 12% likely to open retirement account, 87% likely to consolidate corporate services Consolidated corporate services within 30 days
Retail customer with apparent low balance but high assets in investment platform 84% likely to accept small personal loan offer 8% likely to accept loan, 92% likely to respond to wealth management services Moved $450K to wealth management
Customer with frequent branch visits marked as "digital resistant" in CRM 9% likely to use mobile banking 76% likely to adopt if offered in-branch tutorial (digital app usage detected on other accounts) Became active digital user after branch demo
Customer flagged for retention risk based on checking account activity 78% attrition risk, recommend fee waiver 23% attrition risk, but 91% likely to consolidate accounts if offered relationship pricing Added two new products with relationship pricing

Feature Importance Comparison

The integrated data model shows more balanced feature importance, with relationship depth and cross-product holdings gaining significant predictive power that was previously invisible due to data silos.

Integration Solution Architecture

Creating a unified customer data foundation

Customer Master Data Solution Architecture

1

Data Extraction

Custom connectors extract data from each source system with appropriate frequency

2

Quality & Cleansing

Data is validated, standardized, and enriched

3

Entity Resolution

ML algorithms identify and link records across systems

4

Golden Record

Unified customer profiles with lineage and confidence scores

5

API Services

Secure access to unified customer data

Data Ingestion Layer

Multi-pattern data extraction from source systems with custom connectors for each system's data format and API capabilities.

Apache Kafka Apache NiFi Custom APIs

Data Quality & Cleansing

Rules-based data validation with machine learning for anomaly detection and automated cleaning of common issues.

Great Expectations dbt Spark ML

Entity Resolution Engine

Probabilistic matching algorithm using fuzzy logic and ML to establish customer identity across disparate records.

Custom ML Models Apache Spark Elasticsearch

Master Data Store

Golden record database with lineage tracking, confidence scores and bi-directional synchronization capabilities.

Snowflake GraphDB Redis

Customer Intelligence Layer

ML models for segmentation, propensity scoring, and next-best-action recommendations based on integrated data.

TensorFlow PyTorch MLflow

API & Integration Services

Service layer exposing unified customer data to downstream systems with appropriate access controls.

GraphQL REST APIs Kafka Streams

Entity Resolution Algorithm

import pandas as pd
import numpy as np
from fuzzywuzzy import fuzz
from sklearn.ensemble import RandomForestClassifier
from sklearn.metrics import precision_recall_fscore_support

# Sample function to generate matching features
def generate_matching_features(record1, record2):
    """Generate features for matching two customer records across systems"""
    features = {}
    
    # Name similarity features
    name1 = record1.get('FULL_NAME', record1.get('display_name', f"{record1.get('First_Name', '')} {record1.get('Last_Name', '')}"))
    name2 = record2.get('FULL_NAME', record2.get('display_name', f"{record2.get('First_Name', '')} {record2.get('Last_Name', '')}"))
    
    features['name_token_set_ratio'] = fuzz.token_set_ratio(name1, name2)
    features['name_token_sort_ratio'] = fuzz.token_sort_ratio(name1, name2)
    
    # Phone similarity
    phone1 = str(record1.get('PHONE', record1.get('contact', {}).get('phone', '')))
    phone2 = str(record2.get('PHONE', record2.get('contact', {}).get('phone', '')))
    
    # Normalize phone numbers - remove non-digits and compare last 10 digits
    phone1_digits = ''.join([c for c in phone1 if c.isdigit()])[-10:]
    phone2_digits = ''.join([c for c in phone2 if c.isdigit()])[-10:]
    
    features['phone_exact_match'] = int(phone1_digits == phone2_digits and len(phone1_digits) == 10)
    
    # Address similarity
    # Extract address components in a format-agnostic way
    addr1 = get_normalized_address(record1)
    addr2 = get_normalized_address(record2)
    
    features['address_similarity'] = fuzz.token_set_ratio(addr1, addr2)
    
    # Date of birth comparison
    dob1 = normalize_date(record1.get('DOB', record1.get('Birth_Date', record1.get('birth_date'))))
    dob2 = normalize_date(record2.get('DOB', record2.get('Birth_Date', record2.get('birth_date'))))
    
    features['dob_match'] = int(dob1 == dob2 and dob1 is not None)
    
    # Additional features for confidence calculation
    features['source_system_reliability'] = get_system_reliability_score(record1, record2)
    features['data_completeness'] = calculate_completeness_score(record1, record2)
    
    return features

# Train a matching model with labeled data
def train_matching_model(labeled_pairs):
    """Train a model to predict if two records match based on similarity features"""
    X = []
    y = []
    
    for pair, is_match in labeled_pairs:
        features = generate_matching_features(pair[0], pair[1])
        X.append(list(features.values()))
        y.append(is_match)
    
    model = RandomForestClassifier(n_estimators=100, max_depth=10)
    model.fit(X, y)
    
    return model

# Resolve entities across multiple systems
def resolve_customer_entities(customer_records_by_system):
    """Identify unique customers across system boundaries"""
    all_comparisons = []
    for sys1, records1 in customer_records_by_system.items():
        for sys2, records2 in customer_records_by_system.items():
            if sys1 >= sys2:  # Avoid duplicate comparisons
                continue
                
            for rec1 in records1:
                for rec2 in records2:
                    features = generate_matching_features(rec1, rec2)
                    all_comparisons.append((rec1, rec2, features))
    
    # Apply matching model
    match_predictions = matching_model.predict_proba([list(f.values()) for _, _, f in all_comparisons])
    
    # Create clusters of matching records
    customer_clusters = build_customer_clusters(all_comparisons, match_predictions)
    
    # Create golden records
    golden_records = []
    for cluster in customer_clusters:
        golden_record = create_golden_record(cluster)
        golden_records.append(golden_record)
    
    return golden_records

Business Impact & ROI

67%

Increase in cross-sell conversion rate

42%

Reduction in marketing campaign costs

23%

Increase in customer satisfaction (NPS)

$4.7M

Annual operational cost savings

Educational Insights: The Customer Data Integration Journey

Understanding the Challenge

Banking's legacy technology landscape is a historical artifact of both organic growth and acquisitions. Most institutions face five common data challenges:

These challenges fundamentally limit AI effectiveness because they introduce invisible biases and blind spots in customer understanding.

Learning Principles

The "One Source of Truth" Fallacy

Despite decades of IT initiatives promising "one source of truth," the reality is that enterprises need a strategy for managing multiple sources of truth with varying levels of quality, relevance, and timeliness.

Confidence Over Certainty

Modern data integration relies on probabilistic approaches that assign confidence scores rather than binary judgments, allowing systems to propagate uncertainty through analytical pipelines.

Quality at Source

While cleaning at the integration layer is necessary, long-term solutions require improving quality at each source system through validation, standardization, and governance.

Data Quality Maturity Model

Most organizations begin at Level 1 or 2, with progression to higher levels requiring both technological investment and cultural change in how data is valued.

Implementation Roadmap

Successful integrations follow this implementation sequence, starting with high-value, achievable goals to build momentum and organizational buy-in.

Key Lessons & Implementation Strategy

Start with Business Value

Begin with high-value use cases like retention and cross-sell to demonstrate ROI, rather than boiling the ocean with a complete data integration project.

Probabilistic Matching

Accept that perfect matching is impossible - build confidence scoring into customer golden records and integrate uncertainty into downstream processes.

Agile Implementation

Roll out in phases with iterative improvement cycles guided by data quality metrics and business outcomes rather than technical completeness.

Source System Governance

Apply consistent data validation standards across all source systems to prevent quality degradation over time and reduce cleaning effort.

Data Science Takeaways

Trust your model only as much as you trust your data. A sophisticated model on poor-quality data will deliver poor-quality predictions.

Data integration is not a one-time effort. Business operations continuously generate new data, which must be validated and incorporated into the unified view.

Feedback loops are essential. AI predictions should be tracked against actual outcomes to continuously refine both the data integration pipeline and the models themselves.

Data lineage matters. For regulatory compliance and model explainability, maintain clear records of which source systems contributed to specific customer insights.