Practice : Synthetic Monitoring

Purpose and Strategic Importance

Synthetic Monitoring is the practice of simulating user interactions or requests against your system on a regular schedule to detect issues before real users are affected. It provides proactive visibility into performance, availability, and functionality across environments - including production.

By identifying issues early, synthetic monitoring enhances reliability, reduces incident response time, and builds confidence in both new releases and steady-state operations. It’s an essential part of a robust observability strategy.

Description of the Practice

  • Predefined scripts or test journeys simulate user interactions or service calls.
  • Synthetic checks run on a scheduled basis (e.g. every minute) from multiple regions or data centres.
  • Checks validate availability, latency, transaction correctness, and critical workflows.
  • Alerts are triggered when thresholds are breached or failures occur.
  • Tools include Datadog Synthetics, Pingdom, New Relic Synthetics, AWS CloudWatch Synthetics, and custom scripts.

How to Practise It (Playbook)

1. Getting Started

  • Identify critical user journeys (e.g. login, checkout, API ping) that should be monitored proactively.
  • Use a synthetic monitoring tool to create scripted checks simulating those paths.
  • Schedule checks from multiple regions to ensure global performance.
  • Integrate with alerting tools (e.g. PagerDuty, Slack) to route failures quickly.

2. Scaling and Maturing

  • Add synthetic checks for multiple personas, browsers, devices, and APIs.
  • Correlate synthetic results with real-user monitoring (RUM) for holistic visibility.
  • Use synthetic data in CI/CD pipelines for pre-deployment validation.
  • Review synthetic failures regularly and refine scripts to match evolving UX or APIs.
  • Define service-level objectives (SLOs) based on synthetic performance benchmarks.

3. Team Behaviours to Encourage

  • Treat synthetic failures as serious signals - even if users aren’t impacted yet.
  • Include synthetic coverage in test planning and release sign-offs.
  • Collaborate with product and operations to ensure critical paths are represented.
  • Review synthetic dashboards during on-call, retros, and incident postmortems.

4. Watch Out For…

  • False positives from brittle scripts that break with minor changes.
  • Infrequent checks that miss short outages or slowdowns.
  • Neglecting to update synthetic scripts after product changes.
  • Monitoring low-value or unimportant flows - focus on customer value.

5. Signals of Success

  • Teams detect issues proactively before they affect customers.
  • Synthetic results align with system health and user experience.
  • Release confidence improves due to pre- and post-deploy checks.
  • Synthetic coverage is visible, reviewed, and maintained.
  • Monitoring is used not just for alerting - but for learning and reliability.