How to Keep Testing When Dependent Systems Aren’t Available

Tired of waiting on unreliable third-party systems to test your software? Service virtualization lets you simulate dependencies and keep testing. Read on to learn how service virtualization helps you stay on schedule.

In today’s world of connected applications, your software probably talks to a lot of different systems—APIs, databases, third-party services, partner integrations, and more. To perform any kind of testing in such a system requires standing up all of these components in a production-like environment.

But what happens when one of those systems isn’t available for testing yet? Or worse, what if it’s unstable, unreliable, or owned by a third party you can’t control?

If you’ve ever found yourself stuck waiting for a service to be "ready," you’re not alone. These kinds of delays can bring testing to a standstill. And nobody wants to delay a release just because someone else’s system isn’t available.

That’s where service virtualization can make a big difference.

When Services Aren’t Available, Testing Slows Down

One of the biggest blockers to fast, efficient testing may not be your code, but everything your code depends on.

Modern applications are rarely built as standalone systems. They rely on an ecosystem of services and APIs that all need to be available, stable, and working correctly in order for tests to run smoothly. But that’s not always the case.

Your team might be waiting on:

Internal APIs still in development. You can’t test what doesn’t exist yet, but waiting for that service to be finished slows everyone down.

Third-party systems you don’t control. Whether it’s a partner API, a payment gateway, or an external data provider, if they’re down or rate-limited, so are your tests.

Unstable test environments. Even if the service is technically "available," it might be prone to errors, missing data, or inconsistent responses.

Shared environments across teams. One group’s changes can break another’s tests, or you might have to wait for test data refresh to run test suites, introducing delays into your pipeline.

All of these issues add friction to your testing process. Tests fail, not because your code is broken, but because the environment isn’t ready. Or worse, you can’t run your tests at all, which means:

• You skip regression tests and hope for the best.
• You delay testing until the service is ready.
• You release with limited visibility into system behavior.

None of those options are ideal, especially when you’re trying to keep up with the fast pace of Agile and DevOps. These kinds of delays can throw off your whole delivery schedule. You might miss a release deadline, have to cut corners on test coverage, or end up dealing with unreliable test results. And when you’re not catching issues early, there’s a higher chance defects slip into production, causing headaches for users and even bigger problems for your team down the line.

And the worst part? These delays are often completely out of your control.

That’s why simulating those systems through service virtualization is so powerful. It puts control back in your hands.

Service Virtualization to the Rescue

So what do you do when a critical API isn’t ready, or a third-party service keeps going down? You don’t stop testing—you virtualize.

Service virtualization gives you a smarter way to deal with these kinds of roadblocks. Instead of waiting around for real systems to be available, you create a virtual version. In the past we’ve used mocks and stubs to isolate units under tests, but static mock behavior is not sufficient for complex higher-scope tests that need to honor data and behavior characteristics across the system.

A virtual asset, on the other hand, is realistic simulation that behaves just like the actual API, database, or backend service. It responds to requests, infers conditional logic, reads and writes data and stays consistent no matter what’s happening in the real world.

That means you can start testing earlier, even before the actual service is built or stable. You can simulate third-party services that are unreliable or expensive to access. And you can create test scenarios for tricky edge cases that are hard to trigger in a live environment.

Want to test how your app handles a timeout? Or what happens when a service returns an unexpected error? No problem. You can simulate it all.

More importantly, virtual services give you control. You’re no longer tied to someone else’s schedule or limited by environment instability. Your CI/CD pipeline keeps moving. Your automation stays reliable. And your team doesn’t lose momentum every time a dependent system goes offline.

Think of it like having a smart stand-in for every service your application relies on. It looks and acts like the real thing, but it’s always on, always consistent, and always under your control.

Real-World Example: How Northbridge Financial Solved the Problem

Let’s take a look at how this worked for Northbridge Financial, a leading insurance provider.

Their teams needed to run regression tests on systems that relied on broker partner APIs. But those APIs weren’t always available when testing needed to happen. Sometimes they were still being developed. Sometimes they were just down. And since Northbridge didn’t control them, they couldn’t make them available on demand.

Rather than slow down or delay testing, they used Parasoft Virtualize to simulate those broker APIs.
The results were impressive:

• 90% faster test execution
• 80% more API test coverage
• Testing could continue on schedule. No more waiting for partner systems.

By using stable, reusable virtual services, the Northbridge team kept their testing pipeline running smoothly and met their internal release goals, without being held up by external systems.

Want to hear it directly from the source?

Check out this video interview with Northbridge’s senior QA automation manager, where she shares how Parasoft solutions helped them improve test efficiency, boost API coverage, and maximize ROI across their testing practice.

Why It Matters

This isn’t just a clever workaround. Service virtualization gives your team a real strategic advantage when it comes to testing modern, interconnected applications.

You get:

• Faster feedback loops
• Higher test coverage
• Better reliability in your CI/CD pipeline
• More time to focus on quality, not just availability

And in industries like financial services, where teams deal with a lot of external integrations and compliance pressure, being able to test without waiting is a gamechanger.

Wrapping It Up

If waiting on unstable, unavailable, or third-party systems is slowing your testing down, you’re not stuck. With service virtualization, you can simulate the systems you depend on and keep moving forward, confidently and on schedule.

It’s one of the simplest ways to remove uncertainty from your test cycles and keep your team productive.