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The Painful Truth About Automated Testing: When Writing Tests Takes Longer Than Building the System

Why many engineering teams struggle with testing, and why the answer isn’t simply “write more tests”

Kreingkrai Luangchaipreeda · 2026-06-22 02:01 · 0 claps · 4.8 min read
#automated-testing #software-engineering #unit-testing #integration-testing #test-automation
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The Painful Truth About Automated Testing: When Writing Tests Takes Longer Than Building the System

Why many engineering teams struggle with testing, and why the answer isn’t simply “write more tests”

There’s a moment every developer eventually experiences.

You finish implementing a feature.

The API works.

The UI works.

The database changes are complete.

Everything seems done.

Then someone asks:

“Where are the tests?”

And suddenly the real work begins.

At least that’s how it feels.

I remember one project where implementing a feature took roughly two days.

Writing the automated tests took almost four.

Not because the tests were particularly complicated.

Because the system itself wasn’t designed to be tested easily.

That’s when I learned one of the most uncomfortable truths in software engineering:

Automated testing isn’t expensive because writing tests is hard.

It’s expensive because good tests expose architectural problems.

And that’s exactly why many teams secretly hate them.

The Promise of Automated Testing

When automated testing is discussed online, the benefits sound incredible.

  • Fewer bugs
  • Faster releases
  • Safer refactoring
  • Better code quality
  • More confidence
  • Reduced regression issues

All of those benefits are real.

I’ve seen teams deploy multiple times per day because they trusted their test suite.

I’ve also seen teams terrified of changing a single line of code because they had no tests at all.

The difference is dramatic.

But what rarely gets discussed is the cost.

Because every automated test is software.

And software requires maintenance.

The First Shock: Tests Are Not Free

Many developers treat testing as if it’s a one-time investment.

It’s not.

Every test introduces:

  • Additional code
  • Additional maintenance
  • Additional review effort
  • Additional debugging
  • Additional build time

A feature may be complete.

The tests may pass.

Then six months later a business rule changes.

Now the production code changes.

The tests change.

The test data changes.

The mocks change.

The fixtures change.

Sometimes the tests require more modification than the actual feature.

That reality surprises many teams.

Why Writing Tests Feels Slower Than Writing Features

The reason is simple.

When building a feature, you’re solving one problem.

When writing a test, you’re validating all possible outcomes of that problem.

Imagine implementing:

Create Order

Simple enough.

But testing it may require:

  • Valid input
  • Invalid input
  • Missing customer
  • Out-of-stock products
  • Permission failures
  • Network failures
  • Duplicate submissions
  • Unexpected exceptions

The feature solves one path.

The tests verify every path.

Naturally, the test suite grows larger.

Automated Testing Exposes Bad Architecture

This is where things get interesting.

Whenever I hear:

“Testing this is impossible.”

What I usually translate that into is:

“The code is tightly coupled.”

For example:

Controller
↓
Database
↓
External API
↓
Email Service
↓
File System

all mixed inside one method.

The business logic works.

But testing becomes painful.

You need:

  • Mocks
  • Stubs
  • Fake data
  • Fake APIs
  • Fake services

Suddenly writing the test becomes harder than writing the feature.

Many testing problems are actually design problems wearing a different costume.

The False Goal of 100 Percent Coverage

At some point, many teams become obsessed with coverage numbers.

80%.

90%.

100%.

The problem is that coverage measures execution.

Not confidence.

Consider two scenarios.

Scenario A

100 percent coverage.

But the tests verify almost nothing meaningful.

Scenario B

70 percent coverage.

But critical business workflows are thoroughly validated.

Which system is safer?

Usually Scenario B.

Coverage is a useful metric.

It’s a terrible objective.

Not All Code Deserves Equal Testing

This lesson saved our team an enormous amount of time.

Early in my career, I believed everything should be tested equally.

Now I don’t.

For example:

High Value

  • Payment logic
  • Pricing calculations
  • Permissions
  • Authentication
  • Financial workflows

These deserve strong testing.

Medium Value

  • Business rules
  • APIs
  • Integrations

Test appropriately.

Low Value

  • Simple mappings
  • Basic DTOs
  • Trivial wrappers

Sometimes testing these provides very little return.

The goal isn’t maximum testing.

The goal is maximum confidence.

Those are different things.

Integration Tests Changed My Perspective

For years I focused heavily on unit tests.

Then I noticed something strange.

Many bugs still escaped.

Why?

Because real production failures often happen between components.

Examples:

  • API and database interaction
  • Authentication and permissions
  • Queues and workers
  • Services and external providers

Every individual component worked correctly.

The system didn’t.

That’s when integration testing became a bigger priority.

Because users don’t interact with isolated functions.

They interact with complete workflows.

The Hidden Cost of Fragile Tests

Some test suites become a burden.

Not because they’re large.

Because they’re fragile.

You’ve probably seen tests like this.

Change a button label.

Twenty tests fail.

Rename a field.

Thirty tests fail.

Move a component.

Half the frontend suite explodes.

These tests technically provide coverage.

But they create fear.

Developers begin avoiding improvements because fixing tests takes too much time.

That’s a dangerous place to be.

The Best Tests Rarely Test Implementation Details

One of the biggest improvements in our testing strategy came from changing what we tested.

Instead of asking:

How does this code work?

We started asking:

What behavior should always remain true?

For example:

Bad test:

Verify method A calls method B.

Better test:

Verify an order is created successfully.

Users care about behavior.

Not implementation.

Tests should too.

The Testing Pyramid Is Still Relevant

Despite all the debates, I still find the classic testing pyramid useful.

Unit Tests

Fast.

Cheap.

Focused.

Integration Tests

Validate collaboration between components.

End-to-End Tests

Validate real user journeys.

Many teams accidentally create an upside-down pyramid.

Too many E2E tests.

Too few lower-level tests.

Then build times become painful.

Maintenance becomes expensive.

And confidence decreases instead of increasing.

Why Some Teams Abandon Automated Testing

I’ve seen it happen.

The reasons are usually predictable.

  • Tests are difficult to maintain
  • Build pipelines become slow
  • Coverage targets become political
  • Developers lose trust in failures
  • Test suites become brittle

The problem isn’t testing itself.

The problem is poor testing strategy.

Bad tests create technical debt just as quickly as bad production code.

What We Do Today

Our approach is much simpler than it used to be.

We ask:

What would be expensive if it broke?

Test it thoroughly.

What changes frequently?

Keep tests resilient.

What represents core business value?

Protect it aggressively.

What is trivial?

Avoid excessive testing.

This mindset keeps the test suite manageable while still providing confidence.

The Real Value of Automated Testing

The biggest benefit of automated testing isn’t bug prevention.

It’s confidence.

Confidence to:

  • Refactor
  • Deploy
  • Upgrade dependencies
  • Improve architecture
  • Move faster

Without that confidence, teams become cautious.

And cautious teams eventually become slow teams.

The irony is that testing often feels like it’s slowing development down.

But the absence of testing slows development far more.

The difference just appears later.

Final Thoughts

The painful truth about automated testing is that writing tests often does take longer than writing the feature itself.

Especially when the system grows.

Especially when requirements evolve.

Especially when architecture wasn’t designed with testing in mind.

But that’s not evidence that testing is wasteful.

It’s evidence that software is more complex than it appears.

The best engineering teams don’t measure testing success by the number of tests they write.

They measure it by the confidence those tests create.

Because at the end of the day, the goal isn’t building a large test suite.

The goal is building a system that can continue evolving without fear.

And that’s something every growing software product eventually needs.


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