# Frequently Asked Questions

## General Questions

### What is Metric Engine?

Metric Engine is a Python library for financial calculations with strong typing and policy-driven behavior.

### How do I handle null values?

See [Null Behaviour](concepts/null_behaviour.md) for details on handling null values.

## Common Issues

### Why am I getting unit mismatch errors?

See [Units](concepts/units.md) for information about the unit system.