Prepare the data
Use permissioned, minimised transaction records and separate verified cases from unconfirmed alerts.
Flag unusual activity. Investigate before acting.
Anomaly detection can prioritise unusual records, but unusual behaviour is not proof of fraud. Evaluation must account for scarce verified labels and the cost of unnecessary investigations.
Learning concept · Not a validated service
Anomaly detection can prioritise unusual records, but unusual behaviour is not proof of fraud. Evaluation must account for scarce verified labels and the cost of unnecessary investigations.
A possible application for risk-review teams: Help a small risk team organise evidence for manual investigations. This extension is not delivered by the supplied starter.
Use permissioned, minimised transaction records and separate verified cases from unconfirmed alerts.
Compare an Isolation Forest baseline with simple documented review rules.
Measure precision at the available review capacity and investigate missed verified cases over time.
Build a human review queue with audit notes and no automatic account blocking.
The supplied starter synthesises 300 normal-looking and fifteen suspicious-looking activity records with three numeric fields. IsolationForest assigns inlier/outlier labels, and the script prints the flagged rows.
logs = pd.concat([normal, suspicious], ignore_index=True)
detector = IsolationForest(contamination=0.05, random_state=42)
logs["anomaly_score"] = detector.fit_predict(logs)
alerts = logs[logs["anomaly_score"] == -1]The source uses synthetic activity logs, not validated transaction fraud data. The column called anomaly_score contains discrete labels, not calibrated probabilities. The constructed suspicious rows are not verified fraud, and the starter does not measure alert precision against ground truth.
Proposed extension: Help a small risk team organise evidence for manual investigations.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.