Detect Performance Anomalies | Dataford Interview Questions

Given an array of system metrics, write a utility to identify performance anomalies within a specific time window.

Represent each metric as [timestamp, value]. Implement identify_anomalies(metrics, start_time, end_time, threshold) using an inclusive time window. Within that window, calculate the population mean and standard deviation, and return the original indices whose values differ from the mean by more than threshold * standard_deviation. Return an empty list when the window contains no metrics or all selected values are identical.

Constraints

0 <= len(metrics) <= 9999
Each metric is a two-element array [timestamp, value]
Timestamps and values are real numbers
start_time <= end_time
threshold >= 0
The time window is inclusive
Return indices in ascending input order

Function Signature

def identify_anomalies(metrics, start_time, end_time, threshold):

Your question is Detect Performance Anomalies. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Given an array of system metrics, write a utility to identify performance anomalies within a specific time window.

Constraints

0 <= len(metrics) <= 9999
Each metric is a two-element array [timestamp, value]
Timestamps and values are real numbers
start_time <= end_time
threshold >= 0
The time window is inclusive
Return indices in ascending input order

Function Signature

def identify_anomalies(metrics, start_time, end_time, threshold):

Your question is Detect Performance Anomalies. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.