Design REST API for Metrics | Dataford Interview Questions

Build a small RESTful API that ingests a provided dataset and returns aggregated metrics. Implement the core behavior as aggregate_metrics(records, group_by, metric_fields). Return one result per group, with count, sum, minimum, maximum, and average for every requested numeric field, ordered by group value.

Input records are dictionaries with a string grouping field and numeric metric fields. Return a list of dictionaries with keys group, count, and metrics; return [] for an empty dataset.

Constraints

0 <= len(records) <= 5000
1 <= len(metric_fields) <= 20
Each record contains group_by and every field in metric_fields
Every grouping value is a string
Every metric value is an integer or floating-point number
metric_fields contains unique field names

Function Signature

def aggregate_metrics(records, group_by, metric_fields):

Your question is Design REST API for Metrics. Start with the requirements in the Question tab.

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Problem

Input records are dictionaries with a string grouping field and numeric metric fields. Return a list of dictionaries with keys group, count, and metrics; return [] for an empty dataset.

Constraints

0 <= len(records) <= 5000
1 <= len(metric_fields) <= 20
Each record contains group_by and every field in metric_fields
Every grouping value is a string
Every metric value is an integer or floating-point number
metric_fields contains unique field names

Function Signature

def aggregate_metrics(records, group_by, metric_fields):

Your question is Design REST API for Metrics. 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.