What is APM in software development?

Application Performance Monitoring (APM) gives engineering teams visibility into three questions: is my application fast, is it working correctly, and is it even available? It combines four pillars — metrics (response time, throughput), logs (structured event records), distributed traces (end-to-end request flow across services), and availability checks. APM tools collect this data continuously so teams can detect and diagnose production issues before users report them.

What is the difference between APM and uptime monitoring?

APM measures how a system performs — latency, error rates, resource usage — and tells you why something is slow. Uptime monitoring asks the simpler question: is the service reachable at all? A system can be slow without being down, and intermittently unreachable while showing healthy APM metrics. Both are required — APM without uptime monitoring leaves blind spots for availability failures that backend dashboards never reveal.

How do I add health checks to an ASP.NET Core app?

Call builder.Services.AddHealthChecks() in Program.cs, then expose the endpoint with app.MapHealthChecks('/health'). Uptime monitoring tools will probe this URL on a schedule to verify your app is alive. Add a second endpoint at '/ready' for readiness checks that verify downstream dependencies — databases, external APIs — are also available, not just the process itself.

What is distributed tracing?

Distributed tracing tracks a single request as it flows across multiple services, databases, and external calls. Each service adds a span to the trace, recording start time, duration, and any errors. The result is a complete timeline showing exactly where time was spent at every hop: API processing, database queries, downstream service calls, and network latency. It is the fastest way to identify which component caused a slow or failed request in a multi-service system.

What is synthetic monitoring?

Synthetic monitoring uses scripts that periodically simulate user actions — loading a page, calling an API, submitting a login form — from external locations to verify that your application is available and working correctly. Unlike real user monitoring, which captures actual sessions, synthetic checks run on a schedule and alert you to downtime before users are affected. They are the standard method for tracking uptime SLAs and for detecting soft downtime, where APIs fail while the frontend still loads.

Infoveave Engineering Team·May 2026·Updated May 2026·8 min read

Application Performance Monitoring (APM) in .NET and React — Beyond Just "Is It Working?"

If you've ever pushed a feature to production and thought "it works on my machine, so we're good", you already know how misleading that confidence can be.

In modern applications — especially those built with .NET backends and React frontends — performance issues don't show up in isolation. A slow API, a failing database call, or even a broken frontend request can quietly degrade user experience before anyone notices.

That's where Application Performance Monitoring (APM) comes in.

But APM isn't just about performance anymore. It's about understanding your system end-to-end, including one critical aspect developers often overlook: service uptime.

What APM Actually Means (Without the Buzzwords)

At its core, APM gives you visibility into three fundamental questions:

Is my application fast?
Is it working correctly?
Is it even available?

To answer that, APM combines four pillars:

1. Metrics

Numbers like response time, CPU usage, memory, and throughput.

2. Logs

Structured or unstructured records of events and errors.

3. Traces

The most powerful concept — tracking a request as it flows through your entire system.

Example flow:

React → API (.NET) → Service → Database → Response

4. Availability (Uptime)

Is your service reachable at all?

This is where many teams go wrong. They monitor performance deeply — but forget to ask the simplest question:

"Is my API even responding?"

Uptime Is Not Performance — And That Matters

Let's clear a common misconception.

A system can be up but slow
A system can be fast but intermittently down

Both are problems. Only APM and uptime monitoring together give you the full picture.

What is Uptime?

Uptime is usually expressed as a percentage:

99.9% → approximately 43 minutes downtime per month
99.99% → approximately 4 minutes downtime per month

How Do We Track It?

1. Health Checks (in .NET)

Expose endpoints like /health and /ready. These tell monitoring tools whether your app is alive and ready.

2. Synthetic Monitoring

External systems periodically ping your app:

Is the API responding?
Is login working?
Is the homepage loading?

Key Insight

From a user's perspective: if React loads but APIs fail, the app is effectively down. That's called soft downtime, and frontend monitoring is essential to catching it.

APM in .NET Applications

.NET (especially ASP.NET Core) is very APM-friendly out of the box.

What You Can Track

Request duration
Dependency calls (SQL, HTTP)
Exceptions
Throughput

Health Checks in .NET

csharp

builder.Services.AddHealthChecks();

var app = builder.Build();

app.MapHealthChecks("/health");

app.Run();

This enables uptime monitoring tools to check if your app is alive.

OpenTelemetry Setup in .NET

csharp

builder.Services.AddOpenTelemetry()
    .WithTracing(tracerProviderBuilder =>
    {
        tracerProviderBuilder
            .AddAspNetCoreInstrumentation()
            .AddHttpClientInstrumentation()
            .AddSqlClientInstrumentation()
            .AddConsoleExporter();
    });

This gives you distributed tracing — so you can see exactly where time is spent across every hop in your stack.

APM in React Applications

Backend monitoring alone is incomplete. Your users interact with the frontend, not your API logs.

React APM focuses on real user experience.

What You Should Track

Page load time
API latency from the browser's perspective
JavaScript errors
Failed network requests

Basic Performance Tracking

javascript

import { useEffect } from "react";

function App() {
  useEffect(() => {
    const start = performance.now();

    return () => {
      const end = performance.now();
      console.log("Component load time:", end - start);
    };
  }, []);

  return <div>Hello World</div>;
}

API Failure Tracking

javascript

fetch("/api/data")
  .then((res) => {
    if (!res.ok) {
      throw new Error("API failed");
    }
    return res.json();
  })
  .catch((err) => {
    console.error("API error:", err);
  });

This is crucial for detecting frontend-visible downtime — the kind your backend dashboards will never show.

Popular APM Tools for .NET and React

Here are widely used tools that support both backend and frontend monitoring:

Azure Application Insights
New Relic
Datadog
Elastic APM
Dynatrace

Feature Comparison

Feature	Description
Distributed Tracing	Track a request across services end-to-end
Metrics Dashboard	Visualise performance over time
Error Tracking	Capture and group exceptions
Real User Monitoring	Track actual frontend performance
Synthetic Monitoring	Simulate uptime checks from external locations

Tools like Datadog and New Relic combine APM and uptime monitoring in one place, which reduces context-switching when debugging incidents.

End-to-End Example: Where APM Really Shines

Let's say a user clicks a button in your React app:

React sends a request → .NET API
API calls → Database
DB responds → API → React

Scenario 1: Slow Response

APM trace shows:

API processing: 50ms
DB query: 2 seconds

Root cause found instantly — no guessing, no log-trawling.

Scenario 2: API Down

Synthetic check fails
/health endpoint not responding
Uptime alert triggered automatically

Scenario 3: API Works, But UI Fails

API returns data correctly
React throws a JavaScript error before rendering

Backend looks healthy. Users are stuck. Only frontend monitoring reveals this — and without it, the on-call engineer sees green on every dashboard while support tickets pile up.

Best Practices

1. Monitor What Matters

Don't instrument everything at once. Focus on:

Critical APIs
Login and payment flows
Key user journeys

2. Combine APM and Uptime

APM tells you why it's slow. Uptime tells you whether it's available. You need both — one without the other leaves blind spots.

3. Use Health Checks Properly

/health → basic liveness check (is the process running?)
/ready → readiness check (are dependencies OK?)

4. Avoid Alert Noise

Too many alerts leads to ignored alerts. Instead:

Set meaningful thresholds
Use anomaly detection rather than static limits
Page on symptoms, not causes

5. Think Like a User

Backend success does not equal user success. Always include frontend monitoring as a first-class concern, not an afterthought.

Final Thoughts

APM isn't a nice-to-have anymore — it's a core part of building reliable systems.

If you're working with .NET and React, your system is already distributed across backend services, APIs, browsers, and external dependencies. Without APM, you're debugging blind in production.

And if you're only tracking uptime, you're missing half the story.

The real power comes from combining:

Performance — APM and distributed tracing
Availability — uptime and health checks
User experience — frontend monitoring and real user data

That's how you move from "it works" to "it works reliably for users".

How We Use This at Infoveave

Infoveave runs APM across its own platform — monitoring the .NET backend APIs and React frontend that serve data analytics to enterprise customers. Reliability is non-negotiable when your product is the source of truth for business decisions. A slow query on a dashboard or a dropped ingestion job shows up immediately in APM traces, long before a customer notices. We've found that combining backend tracing with real user monitoring on the frontend is the only way to catch the class of problems where the server reports green but the user experience is broken — latency in third-party API calls, large payload rendering times, and client-side state mismatches. The monitoring stack described in this article reflects how we think about it.

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About the Authors

This article was written by the Infoveave Engineering Team — building Unified Data Platform, agentic BI, and enterprise analytics infrastructure. Infoveave (by Noesys Software) helps organisations unify data, automate business processes, and act faster with AI-powered insights.

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