What software engineers need to know about monitoring vs. observability

In this article, I'll break down the differences between monitoring, observability, and debugging in simple, actionable terms, and explain how they complement each other in helping us keep systems running smoothly.

If you've ever been confused about these concepts, hopefully this post will clear things up.

Monitoring

AKA: Keeping an eye on your system

Monitoring is the practice of keeping an eye on your system's health. Think of it like the dashboard in your car that shows the speed, fuel level, and engine temperature. It gives you real-time data about how things are running so you can spot problems early.

In software, monitoring involves setting up metrics like CPU usage, memory consumption, or error rates, that tell you whether your application is performing as expected. It's all about tracking known issues and having alerts that warn you when something goes wrong.

Here's what monitoring does for you:

• Tracks specific metrics: You know exactly what you're monitoring, whether it's uptime, response times, or error rates.

• Sends alerts: When something goes outside the expected range, monitoring tools send you alerts.

• Shows trends over time: Monitoring tools help you visualize performance trends, so you can spot issues before they escalate.

But monitoring has its limits—it's mostly useful for tracking the known knowns, things you expect to happen or have seen before. If something unusual happens that you didn't anticipate? Well, that's where observability comes in.

Observability

AKA: Understanding the unknowns

While monitoring helps you track specific, pre-defined metrics, observability is about understanding what's going on inside your system - even when you don't know exactly what you're looking for. It's like being able to pop the hood on your car and investigate why the engine light came on.

In practical terms, observability means instrumenting your system in a way that lets you ask new questions and explore how different components behave under varying conditions. The key tools here are:

• Logs: Records of specific events or actions that happened in your system (e.g., "User clicked the login button").

• Traces: Tracks the flow of requests across services, giving you a detailed map of how your system processes data.

• Metrics: Quantitative data points that tell you how much of something is happening (e.g., the number of HTTP requests per second).

The key difference is that observability gives you the ability to explore and discover new issues that your monitoring tools didn't foresee. It can help you answer questions like:

Why is response time slower for users in Europe?
What happened to that request that took longer than usual?
How did this spike in CPU usage affect downstream services?

In short, while monitoring tells you if something is wrong, observability helps you understand why it's wrong.

Debugging

AKA: Getting into the weeds

Once you've detected an issue through monitoring or discovered something unexpected using observability, it's time for debugging.

Debugging is the process of finding and fixing the root cause of the issue. It's the hands-on detective work that we, as engineers, know all too well.

During debugging, you dive deep into the logs, traces, and code to figure out exactly what went wrong and why. This can involve:

• Reproducing the issue: Trying to recreate the problem in a controlled environment.

• Examining logs and stack traces: Looking through detailed error messages and traces to pinpoint where things went off the rails.

• Running local tests: Writing or running tests to isolate the bug and confirm the fix.

Unlike monitoring and observability, which are more about detecting and understanding issues, debugging is where the real problem-solving happens. It's the painstaking process of untangling the knots to get everything back on track.

If you're interested in reducing the effort of manual debugging, capture.dev can automate this process by automatically capturing screenshot, reproduction steps and technical information for you.

How Monitoring, Observability, and Debugging Work Together

Now that we know the difference between these three concepts, it's important to understand how they work together in practice.

• Monitoring gives you a high-level overview of system health and alerts you when something is off.

• Observability helps you dig deeper, providing the tools and data to explore why something isn't working as expected.

• Debugging is the process of finding and fixing the specific issue, often using insights gathered from monitoring and observability tools.

Together, these three steps form a feedback loop that keeps your system healthy and reliable.