The Best 5 Performance Metrics

When teams focus on the wrong metrics, their good intentions do not create the desired impact. By selecting the right metrics, you tell a story that drives actions.

My top 5 performance metrics are

• P95 / P99 response time

• Transaction success rate

• Mean time to recover

• Error rate

• Business impact

Tail latency

Response time metrics are crucial because they demonstrate real-world impact. Frequently, averages are selected, which creates a wrong impression. More important is where most of the response times occur. When 95 percent of all response times are within 2 seconds, or the average is 2 seconds, it makes a huge difference. User Experience is considered the ultimate performance metric. Instead of averages, you should measure the experience of your slowest users. Focus on tail latency that impacts satisfaction.

Trust rate

When requests fail, business outcomes are at risk. A user at checkout is being blocked; payments can't be processed, and stock can’t be purchased. With every failed transaction, a missed opportunity appears which directly impacts revenue. Therefore, the transaction success rate is a crucial metric, as it tracks the percentage of business transactions completed successfully. It is directly tied to reliability and revenue. Remember: Success drives trust and trust drives business.

Operational excellence

Every minute of downtime directly impacts revenue because when digitized services are unavailable, they can’t be consumed by paying customers. Mean time to recover (MTTR) measures how quickly you restore services. Lower MTTR means less impact and happier customers. Speed of recovery defines operational excellence.

Quality is remembered

High error rates are never a good indicator. When services fail due to technical or business errors, customers suffer because they need to repeat their transactions or can’t buy your goods. Error rates show the quality and stability of your system. Fewer errors mean better experiences and lower costs. The saying goes, “Quality is remembered long after the price is forgotten.”

Business grows

Not every digitized service is equally important. When mission-critical services show performance problems, the business suffers. Revenue at risk or business impact quantifies this impact because it keeps the focus on what truly matters. When performance improves, business grows.

Performance is a business metric. By shifting the focus to the right metrics, you will improve what counts for your business!

Happy Performance Engineering!