# ADR-015: Application Performance Monitoring (APM) and Error Tracking

**Date**: 2025-12-12

**Status**: Proposed

## Context

While `ADR-004` established structured logging, the application lacks a high-level, aggregated view of its health, performance, and errors. It's difficult to spot trends, identify slow API endpoints, or be proactively notified of new types of errors.

## Decision

We will integrate a dedicated Application Performance Monitoring (APM) and error tracking service like **Sentry**, **Datadog**, or **New Relic**. This will define how the service is integrated to automatically capture and report unhandled exceptions, performance data (e.g., transaction traces, database query times), and release health.

## Consequences

**Positive**: Provides critical observability into the application's real-world behavior. Enables proactive identification and resolution of performance bottlenecks and errors. Improves overall application reliability and user experience.
**Negative**: Introduces a new third-party dependency and potential subscription costs. Requires initial setup and configuration of the APM/error tracking agent.