Everything You Need to Know About QA Testing in 2025

Testlio

February 24th, 2025

Before releasing software, QA testing assures that it functions appropriately, satisfies user expectations, and is free of serious flaws. It’s more than bug hunting; it’s a process that boosts reliability and user experience.

But what if QA isn’t done right? Bugs slip through, causing frustration, bad reviews, and financial losses. Worse, security vulnerabilities can go undetected, exposing sensitive data to breaches. These performance issues drive users straight to competitors. In some cases, poor QA has sometimes led to major product failures, lawsuits, and long-term brand damage.

TL;DR:

• QA testing guarantees software quality, prevents defects, and enhances user experience.
• A robust QA strategy lowers development costs and accelerates release cycles. 
• Automated and manual testing are essential depending on the project’s needs. 
• Poor QA can result in security flaws, revenue loss, and reputational harm. 

This guide will provide a detailed overview of QA testing, what does it validate, and how to build a successful testing strategy. 

Table of Contents

• What Is QA Testing?
• The Core Principles of Quality Assurance
• QA as Part of a Broader Context
• What does QA Verify and Validate?
• The Roles & Responsibilities of QA Testers
• The QA Process
• Building a QA Team
• Building a QA Testing Strategy
• Determining QA Success Through Essential Metrics
• QA in an Agile Environment
• Applicable Industries
• Common Challenges of QA
• QA Testing Best Practices
• Shifting the Way We Think: The Future of QA
• Final Thoughts

What Is QA Testing?

QA testing is a process used to evaluate software to ensure it meets business requirements, functions as expected, and delivers a smooth user experience (UX). It helps identify defects and ensure security before releasing the software. 

The main goal of quality assurance testing is to build high-quality, reliable software that meets both business and user expectations. 

It helps companies reduce costs by catching defects early and increase efficiency by streamlining development. A well-planned QA process also ensures software runs smoothly, reducing downtime and improving customer satisfaction. 

QA is also an integral part of quality engineering (QE), which embeds quality at every stage of development. While QA ensures software meets functional and security requirements, QE takes a more holistic approach to validating software. It integrates automation, shift-left testing, and continuous monitoring to drive efficiency and innovation across the entire product development lifecycle. QA testing is part of that.

QA Testing Example

Let’s consider QA testing for a ride-hailing app. The app must handle user registrations, ride bookings, real-time GPS tracking, and payments. QA testing will involve multiple activities, including requirement analysis, test planning, design and execution, retesting, reporting, and analysis. 

Without rigorous QA testing, the app could experience payment failure, peak-hour crashes, and security issues. This could frustrate customers, lead to negative reviews, and harm the company’s reputation.

The Core Principles of Quality Assurance

Quality assurance ensures software is functional and meets business objectives. It prevents defects and ensures long-term product stability. Here are the key principles that drive effective QA:

1. Defect prevention over detection
   The goal of QA isn’t to find and fix bugs; it’s to prevent them from occurring in the first place. A strong QA strategy integrates early testing, clear requirements, and risk management to reduce defects before they reach production.
2. Process-driven quality
   QA is most effective when built on repeatable, standardized processes. Well-defined testing methodologies and automation frameworks ensure consistent results across different projects.
3. Continuous improvement
   Software development evolves, and so should QA. A good QA process includes regular feedback loops, post-mortems, and retrospective analyses to refine strategies and enhance testing efficiency over time.
4. Risk-based testing
   Not all defects carry the same weight. QA teams must prioritize testing based on business impact, security concerns, and user-critical functionality. This ensures that high-risk areas receive the most attention.
5. Collaboration across teams
   Quality isn’t a QA team’s responsibility; it’s a shared effort between developers, product managers, and stakeholders. QA should be embedded in the development lifecycle, fostering a culture where everyone owns quality.
6. Measurable and data-driven decisions
   QA should rely on metrics, analytics, and test coverage reports to track progress and make informed decisions. Clear KPIs, such as defect density and test effectiveness, help teams continuously refine their approach.

QA as Part of a Broader Context

Quality assurance is a crucial element of software quality, but it isn’t the whole picture. QA sits within the broader discipline of quality engineering (QE), which adopts a holistic approach to ensuring high-quality software.

By integrating QA early and aligning it with business objectives, companies can improve software reliability, enhance customer satisfaction, and gain a competitive edge. 

However, as software development becomes more complex, organizations must move beyond traditional QA toward a more integrated quality engineering strategy.

The role of QA in the software development lifecycle (SDLC)

At each phase of the SDLC, QA plays a different role:

• Early stages (planning and design): QA helps define quality standards, set testing strategies, and align development with business goals.
• Development and testing: QA ensures early bug detection through automated and manual testing, minimizing rework and improving efficiency.
• Deployment and maintenance: QA supports continuous monitoring, performance optimization, and user feedback analysis to maintain software quality post-release.

Moving from QA to QE

Traditional QA focuses on functional validation, but modern quality engineering integrates DevOps, shift-left testing, and automation to optimize the entire SDLC. This approach breaks down silos between development and testing, leading to:

• Faster software releases
• Reduced costs and technical debt
• Higher customer satisfaction and business value

Organizations can move past detecting defects by positioning QA as part of QE. They can ensure scalable, efficient, and high-performing software by embedding quality at every stage of development.

What does QA Verify and Validate?

QA testing ensures that software meets quality standards before release. It validates different aspects of a product to confirm it works as expected in real-world conditions. Below are the key areas QA helps validate and the testing methods used for each.

Functionality

QA confirms that the software performs its intended tasks correctly. Functional, unit, and integration testing ensure features work as expected and updates do not break existing functionality.

Usability

QA ensures a product is easy to use. Usability testing assesses navigation, clarity, and accessibility to identify design flaws, while accessibility testing ensures compliance with WCAG and ADA standards. The goal is to confirm users can interact with the software without frustration.

Efficiency

Slow performance frustrates users. QA conducts performance, stress, and load testing to measure speed, responsiveness, and system stability under heavy usage. These tests prevent lag and system crashes.

Reliability 

Software should work consistently. Users expect a stable product that doesn’t crash or fail. Reliability testing measures uptime and detects weak points. In contrast, endurance testing ensures long-term stability. If a system breaks under continuous use, QA catches it before release.

Portability 

Software should work across different environments and load conditions. A web app must run on various browsers. Likewise, a mobile app must function on iOS and Android. QA uses portability testing to verify compatibility across devices, operating systems, and configurations. 

Maintainability 

Code should be easy to modify and improve. Poorly structured code slows future development. QA assesses modularity, documentation, and technical debt. Maintainability testing ensures updates, bug fixes, and enhancements can be made efficiently without introducing new problems.

Compatibility 

Software must interact correctly with other systems. Users may rely on different devices, browsers, or third-party integrations. Compatibility testing ensures smooth operation across various environments. It verifies whether updates, plugins, and hardware differences affect performance. Without this, the software may function only in limited conditions.

Security

Cyber threats are a major risk. To this end, QA protects sensitive data by identifying and eliminating vulnerabilities. For instance, QA will test penetration and simulate attacks to find vulnerabilities. Vulnerability assessments identify weak points before hackers do. If security is ignored, sensitive data may be exposed.

APIs 

APIs enable software systems to communicate. If an API fails, entire services can break. QA tests API reliability, data handling, and response accuracy. API testing confirms error handling, request-response integrity, and integration stability. This prevents communication failures between connected systems.

By validating these aspects, QA helps build reliable, high-performing software that meets user expectations.

The Roles & Responsibilities of QA Testers

QA testers play a critical role in software development. They ensure products meet quality standards before release. Their responsibilities cover multiple areas, from identifying bugs to improving user experience.

Key QA Roles

• QA tester: Executes test cases, finds bugs, and reports issues. Ensures software works as expected through manual and automated testing.
• QA engineer: Designs test plans, writes automation scripts, and improves testing processes. Works closely with developers to prevent defects early.
• QA lead: Oversees testing efforts, manages the team, and ensures test strategies align with project goals. Reviews reports and provides insights to stakeholders.
• QA manager: Defines quality standards, implements best practices, and ensures testing aligns with business objectives. Leads risk management and process improvement.

Key QA Responsibilities

1. Designing test cases: Testers design detailed test cases to cover all possible scenarios. These cases outline steps to verify functionality, performance, and usability. Well-designed test cases ensure thorough coverage and reduce the risk of missing critical issues.
2. Executing tests: QA testers run manual and automated tests to identify bugs. They check for errors in functionality, performance, and user experience. This involves using tools, simulating user actions, and documenting results.
3. Reporting bugs: When testers find issues, they report them clearly and concisely. Bug reports include steps to reproduce the problem, expected vs. actual results, and severity levels. This helps developers fix issues efficiently.
4. Collaborating with teams: QA testers work closely with developers and designers. They provide feedback, suggest improvements, and help refine product quality. Communication between teams ensures smooth development.
5. Automating tests: Testers often write and maintain automated test scripts. Automation speeds up repetitive tasks and ensures consistent testing. However, they must choose the right tests to automate and keep scripts updated.
6. Validating security: QA testers play a role in ensuring software security. They test for vulnerabilities, such as weak authentication or data leaks. Security testing helps protect user data and build trust.
7. Reviewing user feedback: After release, testers analyze user feedback to identify areas for improvement. They use this information to refine testing processes and ensure future updates meet user needs.

The QA Process

The QA process follows a structured approach to ensure software quality. Here are the key steps involved:

1. Requirement analysis
   The QA team collaborates with stakeholders to understand project goals and specifications. This step ensures clarity and alignment on what needs testing.
2. Test planning
   The team creates a comprehensive plan outlining the testing strategy, objectives, scope, tools, and team responsibilities.
3. Test case development
   The team designs detailed test cases that define input conditions, execution steps, and expected results. This helps ensure thorough test coverage.
4. Environment setup
   A test environment is prepared to match real-world conditions, ensuring accurate and reliable test results.
5. Test execution
   The QA team runs test cases, documents issues, and collaborates with developers to resolve defects.
6. Test cycle closure
   The team reviews test results, documents findings, and prepares reports. This step ensures all objectives have been met before release.
7. Regression testing
   After changes are made, previously conducted tests are re-run to confirm that new updates haven’t introduced issues.

Building a QA Team

Building a dedicated QA team is key to delivering a high-quality product, and it starts by keeping testing separate from development. While having your star developers handle testing might seem efficient, this approach often backfires. 

Developers are at their best when coding, not trying to mimic user behavior. When engineers split their focus, you risk slower releases, increased turnover, and a product that might not fully reflect the end-user experience.

Here are some key strategies for building a high-performing QA team

• Hire dedicated QA professionals
  Skilled testers bring a fresh perspective by thinking like your end users. Their focused approach helps catch bugs and usability issues developers might overlook, ensuring your product meets real-world demands.

• Embrace flexible staffing models
  Flexible staffing can adapt to your project’s needs, whether you outsource or tap into crowdsourced testing. This approach scales testing efforts during peak periods and helps manage costs, especially when budgets are tight.

• Leverage automation where it counts
  QA Automation is ideal for handling repetitive tasks, allowing manual testers to concentrate on complex, high-impact areas. A balanced mix of automation and human insight drives efficiency without compromising quality.

• Prioritize quality in hiring
  As you rigorously vet your developers, ensure your QA hires are equally exceptional. High-caliber testers are an investment that can save time and money by preventing costly errors later on.
• Optimize your QA budget
  Smart staffing shouldn’t only be about hiring the right talent but also about being cost-efficient. Collaborate with your finance team to prioritize essential QA investments, and consider leveraging scalable staffing options like outsourcing or crowdsourced testing during peak periods. 

  This way, you maintain robust testing without overspending, ensuring your QA efforts drive maximum impact even with a tight QA budget.

Building a QA Testing Strategy

A well-planned QA strategy ensures software reliability and efficiency. Here are some best practices to build an effective QA testing strategy:

1. Align QA with business goals

Testing shouldn’t just focus on catching bugs – it should align with business objectives. Understand how software quality impacts user experience and performance. A strong QA strategy supports the company’s vision by preventing costly failures and ensuring smooth functionality.

2. Develop a comprehensive QA test plan

A well-defined QA test plan is the foundation of an effective testing strategy. It outlines the testing scope, methodologies, resources, and success criteria. A structured test plan ensures consistency, reduces gaps in testing, and aligns teams on expectations.

3. Balance automated and manual testing

While automation speeds up regression testing and repetitive tasks, manual testing remains essential for exploratory, usability, and edge-case testing. The right balance ensures efficiency without sacrificing quality. Define clear guidelines on when to automate and when to rely on human testers.

4. Integrate QA early in development (shift left testing)

Delaying testing until the final stages leads to expensive fixes. Instead, incorporate QA from the start—review requirements, perform early-stage testing, and integrate continuous testing into CI/CD pipelines. This approach reduces defects and shortens release cycles.

5. Use risk-based testing

Not all features carry equal risk. Prioritize testing based on business impact, complexity, and user interaction. Critical functionalities like payment processing or security components should undergo more rigorous testing, while lower-risk areas can have lighter testing efforts.

6. Continuously improve

Track key QA metrics such as defect density, test coverage, and mean time to detect (MTTD) issues. Regularly analyze test results and feedback to refine testing processes. A data-driven QA strategy helps optimize resources and improve software quality over time.

By following these best practices, companies can build a robust QA strategy that enhances product quality and accelerates software delivery. 

Determining QA Success Through Essential Metrics

QA metrics help teams track progress, improve efficiency, and ensure software meets quality standards. Without the right metrics, it’s easy to focus on numbers that don’t give a clear picture of actual performance.

As said by Putu Kusumawardhani, Associate Director, Testing Delivery at Testlio:
“Not all metrics are created equal. Focus on metrics that offer deep insights into the effectiveness and efficiency of the QA process. Prioritizing these metrics over vanity metrics will ensure a more effective and focused QA strategy”. 

Key Metrics to Track QA Success:

• Effort and schedule variance: Tracks deviations from planned timelines and effort estimates.
• Rework effort ratio: Measures the percentage of effort spent on fixing issues versus initial development.
• Defects per test/requirement: Evaluate how many defects arise per test case or requirement.
• Addressed issues: Tracks the number of critical defects fixed after testing.
• Escaped bugs: Measures defects missed during testing but found in production.

QA in an Agile Environment

Agile has transformed QA from a final checkpoint to a continuous, integrated process. Testing now happens throughout development, catching issues early and reducing costly fixes. Automation plays a key role, ensuring stability while keeping up with rapid release cycles.

Collaboration is another major shift – QA teams work alongside developers and product owners, influencing product design and ensuring quality at every stage. While Agile prioritizes speed, QA is essential in balancing fast delivery and reliability.

With continuous testing and shared responsibility, Agile Quality Assurance ensures software meets user expectations while staying adaptable to change. 

Applicable Industries

QA testing plays a vital role in many industries. It ensures products and systems meet safety, reliability, and performance standards. 

Below are key industries where QA is essential.

• Healthcare: Medical software and devices must undergo extensive testing to guarantee accuracy and compliance. In electronic health record (EHR) systems, for instance, quality assurance testing is essential because it guarantees accurate patient records, guards against data loss, and confirms adherence to HIPAA rules.

• Aerospace: For passenger safety, aerospace aircraft systems must operate without a hitch. Avionics software is validated via QA testing, ensuring communication networks, navigational tools, and autopilot systems function in harsh environments. Any malfunction in these systems might have disastrous repercussions.

• Manufacturing: Automated production lines rely on software-driven machinery. QA testing ensures that control systems operate correctly, preventing defects in mass production. For example, in semiconductor manufacturing, QA ensures precision in chip fabrication, reducing errors and waste.

• Automotive: Modern cars use embedded software for engine control, driving aid, and navigation. QA testing confirms that autonomous driving capabilities and anti-lock braking systems (ABS) operate as intended in a variety of road situations. Lethal accidents could result from a single defect in these systems.

• Food and beverage: Automated processing and packaging systems rely on software to maintain precision and safety. QA testing ensures that temperature control systems in pasteurization units function correctly, preventing foodborne contamination. In large-scale beverage production, software testing verifies that automated filling and sealing machines operate accurately to maintain product consistency and compliance with safety regulations.

• Construction: Software is used for project management, structural design, and safety monitoring in construction. QA testing ensures that architectural modeling tools generate accurate designs and prevent structural miscalculations. A flaw in a digital blueprint could lead to costly construction errors.

• Banking & finance: Financial transactions must be secure and error-free. QA testing in banking software ensures that payment processing systems, fraud detection tools, and online banking platforms operate without failures. For example, QA prevents double transactions in credit card processing.

• Telecommunication: Network providers rely on software to manage data flow and connectivity. QA testing ensures that mobile applications, network infrastructure, and call-routing systems function seamlessly. For instance, QA helps prevent dropped calls and ensures smooth video streaming.

Each industry depends on QA to maintain safety, efficiency, and reliability. Without proper testing, businesses risk failures that could harm users, damage reputations, and lead to regulatory penalties.

Common Challenges of QA

Quality assurance in software testing ensures high-quality product outputs for end users. However, achieving this comes with challenges like unstable testing environments, limited resources, and repetitive tasks. 

Here are the challenges QA teams face:

Unstable testing environments

• QA teams often deal with unstable testing environments. 
• Server crashes and frequent restarts disrupt the testing process. 
• This instability leads to delays and affects test results. 

Tight deadlines

• Meeting tight deadlines is a common issue. 
• Rapid development cycles can limit thorough testing, resulting in overlooked defects and defective product quality.  

Inadequate communication

• Poor communication between development and testing teams can cause misunderstandings.
• Misaligned expectations lead to missed requirements and defects. 
• Effective collaboration is essential to prevent these issues. 

Limited resources

• QA teams often face limited resources, including time, budget, and personnel. 
• These constraints make achieving thorough test coverage challenging. 
• Prioritizing critical tests becomes necessary under such limitations. 

Frequent requirement Changes

• Changes in project requirements during development pose challenges. 
• QA teams must adapt test cases to align with new requirements to ensure comprehensive testing.

Repetitive tasks

• Manual testing often involves repetitive tasks, leading to boredom and decreased motivation among testers. This monotony can result in overlooked defects.
• Implementing automation can alleviate this issue. 

QA Testing Best Practices

Following best practices in QA testing is crucial to ensure software quality and reliability. Here are some QA testing best practices to ensure high-quality software delivery.:

• Automate where it makes sense: Automating repetitive tests saves time and reduces human error, but not every test needs automation.
• Test early and often: Catching issues in the early stages of development helps prevent costly fixes later.
• Focus on high-risk areas: Not all application parts need the same testing level. Prioritize areas that are critical to functionality and security.
• Think like a user: A product that works technically but is frustrating won’t succeed. UX testing helps ensure a smooth experience.
• Test performance under real conditions: Applications should handle peak traffic, heavy loads, and slow network speeds without breaking.
• Keep security in mind: Regular security testing helps identify vulnerabilities before attackers do.
• Ensure everything works together: Integration testing confirms that different systems and services communicate properly.
• Collaborate across teams: QA isn’t just a tester’s job. Developers, designers, and product managers all play a role in quality.

Shifting the Way We Think: The Future of QA

Quality assurance in software testing has undergone a significant transformation over the years. No longer the last line of defense, catching the bugs just before release, QA is now a key driver for product quality and business value. 

Traditionally, QA was often labeled as a cost center or an obstacle to rapid releases. However, that perception is no longer valid. By repositioning QA as a value driver, organizations unlock benefits like improved product reliability, reduced post-release fixes, and faster iteration cycles. This paradigm shift encourages teams to view testing not as a tedious final step but as a creative and collaborative effort that fuels innovation. 

As Putu says,
QA is evolving “from a necessary cost to a strategic asset” – a shift that can redefine the way companies achieve excellence in their products.

The evolving role of AI in QA

Artificial intelligence (AI) is rapidly reshaping how we approach software quality assurance. AI tools help create test cases, refactor test plans, and predict potential issues, freeing QA professionals to focus on challenges that demand human creativity and intuition. 

The ‘shift left’ movement emphasizes testing earlier in the SDLC to identify and fix defects sooner, reducing costs and delays. However, it hasn’t replaced the need for manual testing. Instead, the most effective strategies combine automation’s speed with the thoughtful analysis only humans can provide.

A collaborative future

The future of QA is in a balanced, collaborative approach. Imagine an environment where AI handles routine tasks like regression testing while human testers dive into a product’s aesthetic, functional, and user experience nuances. 

This combination enhances efficiency and ensures a richer, more user-focused product experience. By blending cutting-edge automation with critical human oversight, QA transforms from a bottleneck into a catalyst for innovation.

Final Thoughts

Quality assurance has come a long way from simply being the final bug-check. Today, QA testing is a vital part of the entire development process, ensuring that software not only works but also delights its users.

If you’re looking to boost your testing efforts, consider the benefits of QA outsourcing. Companies like Testlio connect talented testers with businesses that need their expertise, providing a flexible way to enhance your QA process. This collaborative approach helps ensure that every release is both reliable and user-friendly.

Reach out today to learn how Testlio can help drive your software development forward and achieve exceptional quality.