Engineering 12 min readMay 03, 2026

Engineering the Sentinel: Architecting a 10M-Record Fraud Detection System

Engineering the Sentinel: Architecting a 10M-Record Fraud Detection System
LOG_ID: ARCHITECTING-10M-RECORD-FRAUD-SENTINEL
Datta Sable
Datta Sable
BI & Analytics Expert

In the financial services sector (BFSI), fraud detection isn't just a feature—it’s the primary line of defense. When dealing with 10,000,000+ transactions, a system must be more than fast; it must be surgically precise.

"Fraud detection is a race against latency. Every millisecond of delay is a window of opportunity for an anomaly to slip through." — Datta Sable

The Challenge: Identifying Needles in a 10M-Record Haystack

Traditional threshold-based systems often fail at scale because they generate too many "False Positives." For the BFSI Sentinel project, I focused on building a multi-dimensional risk-scoring engine that evaluates transactions across several vectors simultaneously.

The Sentinel Core: Technical Milestones

1. Advanced Risk Scoring (ARS)

Instead of simple "If-Then" logic, the Sentinel evaluates transactions using a weighted Risk Score. By correlating Transaction Amount, Temporal Velocity, and Regional Risk Deltas, the system assigns a high-fidelity score that allows investigators to prioritize the most suspicious activities instantly.

2. Performance Benchmarking with DuckDB

To ensure sub-second response times on 10M rows, the Sentinel utilizes a Columnar Storage Engine. This allows the system to scan millions of "Risk_Score" values without loading the entire dataset into memory, maintaining a lightning-fast UI even during heavy auditing cycles.

Visualization as a Diagnostic Tool

In fraud investigation, clarity is king. I engineered a high-contrast Investigation Deck that uses color-mapping to highlight anomalies. High-risk transactions are instantly "Red-Flagged," allowing analysts to drill down into the raw data in milliseconds.

The BFSI Sentinel is a testament to what is possible when data engineering meets professional rigor. Explore the full architecture on my GitHub Sentinel Repo.

Datta Sable
VERIFIED-AUTHOR

Datta Sable

Senior BI Developer & Data Architect with over 10 years of experience in engineering high-fidelity analytics systems. Specialized in Tableau, Power BI, SQL, and Python-driven automation for enterprise-grade decision clarity.