Thorough Functional Testing Services

Functional testing answers one question: does the software do what it was specified to do. Every input, every output, every branch of the business logic is checked against the requirement it came from, so a feature that was signed off in a document behaves the same way in the running product.

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10+Years of Industry Expertise 200+Talented Developers 90%Customer Satisfaction Rate

AgileTech Vietnam open-plan development office

ISO 9001:2015 Certified ISO 27001:2013 Certified

What Clients Say About Our Functional Testing Services

Independent reviews from Clutch and DesignRush. Every review below is shown in full and links back to its source platform so you can confirm it yourself.

4.9/5.0 12 reviews View all reviews on Clutch

5.0/5.0 6 verified reviews View all reviews on DesignRush

5.0

Mar 2026

“The team demonstrated strong professionalism, reliability, and a proactive approach throughout the project.”

AgileTech Viet Nam developed a scalable engineering workflow system for an ICT company. The goal was to streamline internal processes, improve cross-team visibility, and enhance coordination. The system significantly improved operational efficiency by reducing manual processes and increasing transparency across teams for the client. AgileTech Viet Nam set clear milestones and provided regular updates to ensure everyone remained in sync. Their professionalism and reliability stood out.

Scalable engineering workflow system with fewer manual processes

5.0

Jun 2025

“Their proactive communication, flexibility, and technical expertise stood out throughout the project.”

AgileTech Viet Nam used React Native to develop an iOS and Android app for a real estate platform. The team integrated the app with the client’s backend and implemented property search features. AgileTech Viet Nam’s high-quality work resulted in a 30% increase in user registrations and over 1,000 app downloads within the first month. The team delivered on time, provided regular updates, and responded to feedback. Their flexibility and proactive communication impressed the client.

30% more sign-ups and 1,000+ downloads in the first month

5.0

May 2026

“They followed a structured Agile approach with clearly defined milestones.”

AgileTech Viet Nam developed a web-based logistics management system for an automotive parts supplier. The team integrated the platform with third-party providers and built a real-time tracking dashboard. AgileTech Viet Nam’s work reduced manual processing by 55%, improved real-time shipment visibility, and increased operational efficiency across multiple departments. The team followed a structured Agile approach, communicated consistently, delivered on time, and was flexible.

Manual processing reduced by 55% with real-time shipment visibility

5.0

May 2026

“They were not just executing tasks but were genuinely invested in the product’s success.”

AgileTech Viet Nam developed an MVP for a digital solutions provider’s marketplace platform. They created the UI/UX design, developed the front- and backend, and integrated payment systems. AgileTech Viet Nam successfully launched the MVP on time, allowing the client to onboard 500 users within two months. The platform was stable with minimal issues. Moreover, the team was collaborative, flexible, quick to adapt to changing priorities, and genuinely invested in the project’s success.

MVP launched on time, 500 users onboarded within two months

5.0

May 2026

“Their ability to handle both high-level architecture and hands-on implementation is rare.”

An IT services company hired AgileTech Viet Nam to re-architect their enterprise SaaS platform. The team conducted a technical audit, designed a new architecture, migrated legacy data, and added API gateways. Thanks to AgileTech Viet Nam’s work, the client saw improvements in system scalability, platform uptime, and deployment time. The team followed the Agile methodology, communicated effectively, and was responsive to the client’s feedback. AgileTech Viet Nam helped the client make better decisions.

Improved scalability, uptime, and deployment time on an enterprise SaaS

5.0

May 2026

“Their balance between technical expertise and product thinking stood out.”

AgileTech Viet Nam developed an AI-powered analytics platform for an AI visibility and GEO solutions company. The platform featured real-time reporting dashboards and data processing pipelines. AgileTech Viet Nam’s work improved the client’s data processing efficiency and the accuracy of AI-generated insights. The platform was user-friendly and supported the client’s first large-scale deployments. AgileTech Viet Nam’s team was communicative, adaptive, and technically proficient.

Improved data-processing efficiency and AI insight accuracy

5.0

May 2026

“They were flexible in accommodating evolving business needs while still keeping the project on track.”

AgileTech Viet Nam developed a digital platform for a real estate firm. They designed the UI/UX, implemented advanced search and filtering functionalities, integrated dashboards, and automated reporting tools. The platform improved operational efficiency, business performance, lead conversion rates, and customer responsiveness. AgileTech Viet Nam implemented a well-structured project management approach, meeting timelines and responding to feedback with flexibility. Their tailored solutions stood out.

Improved efficiency, business performance, and lead conversion

5.0

Nov 2024

“The platform has greatly improved our operational efficiency, and we wholeheartedly recommend AgileTech.”

Working with AgileTech has been an amazing experience, especially when it comes to creating a personalized e-learning program for our IT services business. We were pleasantly surprised by how adaptable and scalable the platform developed by the AgileTech Team was. Their proficiency with user-friendly course administration and community participation technologies enabled us to provide a thorough instructional resource catered to our customers’ particular requirements. The platform has greatly improved our operational efficiency, and we are amazed by its capacity to manage heavy traffic with ease and offer comprehensive reporting and analytics. The platform remained successful and user-friendly because of the team’s dedication to continuous support and their quick response to criticism. For any organization looking to create innovative and reliable digital solutions, we wholeheartedly recommend AgileTech as a partner.

Personalized e-learning platform that handles heavy traffic

5.0

Nov 2024

“They used a potent tech stack including PHP, React, and AWS to guarantee perfect scalability and zero downtime.”

AgileTech provided a superb Learning Management System (LMS) that creatively and precisely addressed the intricate needs of our organization. Within a scalable, completely customizable platform, the LMS made it possible to create comprehensive courses, administer student tests, engage the community, and obtain real-time data insights. AgileTech’s modular and agile approach made sure that every component, from the user-friendly course builder to the sophisticated analytics and communication tools, was customized to meet our demands despite the difficulties of developing such a feature-rich system. In order to guarantee perfect scalability and zero downtime, even with high user concurrency, AgileTech used a potent tech stack that included PHP, React, and AWS. Their post-launch assistance, which included frequent training sessions and upgrades, gave our staff the means to fully use the LMS’s potential. This project was a testament to AgileTech’s technical skill, rapid deployment, and dedication, making them an outstanding choice for educational technology development.

Feature-rich LMS with course builder, analytics, and comms

5.0

Nov 2024

“We saw huge cost savings and optimized stock levels, so we consider AgileTech a partner in our company transformation.”

AgileTech created a working Supply Chain Management (SCM) system that has helped our supermarket chain simplify operations across inventory management, demand forecasting and logistics. They integrated our existing systems, automated inventory and logistics and gave us robust demand forecasting with AI, we saw huge cost savings and optimized stock levels. And they continued to deliver on quality post launch with regular updates and training sessions, so we consider AgileTech as a partner in our company transformation.

AI-driven demand forecasting across inventory and logistics

5.0

May 2026

“Their professionalism, responsiveness, and ability to execute efficiently made them feel like an operational partner.”

AgileTech Viet Nam optimized a workflow for a consulting firm. The team improved lead management processes and streamlined internal communication systems across multiple departments. AgileTech Viet Nam’s work improved the client’s operations, customer communication process, and overall workflow efficiency. The team was strategic and reliable. Moreover, AgileTech Viet Nam worked closely with the client to understand their business objectives and recommend solutions.

4.5

Apr 2021

“They are incredible to work with and are truly passionate about technology and our concept.”

AgileTech Viet Nam provides mobile app development services for a social media startup. They are building the app using Node.js and Flutter. With the ongoing partnership, AgileTech Viet Nam’s passion has impressed the client so far. The team is truly into technology, and their concept makes the client feel confident about the project’s continuous success.

4.0

Jun 2019

“I was impressed with the flow of the project.”

AgileTech Viet Nam developed a mobile app from scratch. After helping with scoping and objective formation, AgileTech created design mockups and developed the full iOS and Android solutions. Valuable user data is being gathered in ongoing beta tests, which will soon lead to growth and expansion opportunities. AgileTech Viet Nam provided consistent communication and established a smooth workflow. Issues were raised proactively, allowing fixes to come earlier in the process.

5.0

Nov 2024

“AgileTech excelled in supporting our project from initial mock-ups through to the final delivery on the App Store.”

AgileTech excelled in supporting our project from initial mock-ups through to the final delivery on the App Store, incorporating data analytics that we could easily share with our customers. The scope of work included mock-up creation, UI/UX design, interactive prototyping, app development, rigorous testing, and setting up a secure production environment on AWS, culminating in the apps release on both iOS and Android platforms.

5.0

Nov 2024

“Since we launched our new site we’ve seen a significant increase in traffic and sales, which proves their work is effective.”

We’ve had an amazing experience with AgileTech for our eCommerce platform. The team worked with us to build an user friendly online store that met all our business needs. Their eCommerce development expertise was evident from the start as they shared valuable insights on how to maximize sales. The AgileTech team are not only talented but also care about their clients success. Since we launched our new site we’ve seen a significant increase in traffic and sales which proves their work is effective.

5.0

Nov 2024

“Their attention to detail in web development and UI/UX design has given us a site that looks great and works flawlessly.”

Working with AgileTech has been a game changer for us. We wanted a modern and responsive website and AgileTech delivered more than we expected. The team was super collaborative and involved us in every step of the process. Their attention to detail in web development and UI/UX design has given us a site that looks great and works flawlessly. The AgileTech team members are not only talented professionals but also great communicators, so we could share our vision and ideas easily. They were so committed to our success and the end result has increased our user engagement and satisfaction so much.

Explore all 16 client testimonials

Benefits of Functional Testing

Explore the benefits AgileTech Vietnam delivers for every functional testing services engagement.

Defects Found Against a Requirement, Not an Opinion

A functional defect is only meaningful if it can be traced to something that was agreed. We design test cases from your requirements, user stories, or acceptance criteria, so every report cites the specific expectation that was not met. That removes the argument about whether a behaviour is a bug or a preference, which is usually where triage time disappears.

Coverage of the Paths Nobody Planned For

Requirement-based cases confirm the intended behaviour. Exploratory sessions look for what happens outside it: fields left empty, actions taken out of order, sessions that expire mid-flow, records that already exist. Users find these paths within days of release, so it is cheaper to find them first.

A Regression Safety Net Before You Automate

Automation is only worth building once you know which checks matter and that they are stable. Functional testing establishes that set. It produces the documented cases and the priority order that an automation suite is later built from, which is why running it first usually makes the automation cheaper.

Our Functional Testing Process

Six phases from requirement review to a signed-off regression pack, with the ambiguities surfaced before the testing rather than during it.

Requirement Review and Clarification

We read the requirements, user stories, or specifications and list every statement that is ambiguous, contradictory, or silent on an obvious case. This list goes back to you before any test is written. A requirement that cannot be tested cannot be built correctly either, so this phase frequently prevents defects rather than finding them.

Test Planning and Scope Agreement

We agree what is in scope, what is explicitly out, which environments and data are needed, and what the entry and exit criteria are. Scope is written down because an untested area discovered after release is far more damaging when nobody had recorded that it was excluded.

Test Case Design

Cases are written from the requirements using equivalence partitioning and boundary analysis, with negative and edge cases designed deliberately rather than added later. Each case states its precondition, its steps, and the expected result, so a different engineer can run it and reach the same verdict.

Execution and Exploratory Testing

Designed cases are executed and recorded, then time is deliberately reserved for unscripted exploratory sessions. Scripted execution proves the specified behaviour; exploratory work finds the behaviour nobody specified. Both are needed, and a plan containing only the first is incomplete.

Defect Reporting and Retest

Defects are reported with reproduction steps, environment, evidence, the requirement breached, and a severity we can justify. After a fix we retest the defect and the area around it, because a fix that resolves one case while breaking an adjacent one is a common and expensive pattern.

Regression Pack and Handover

We consolidate the stable, repeatable cases into a regression pack and hand it over with the coverage map. The pack is yours: it can be run by your team, extended in later phases, or used as the specification for an automation suite.

AgileTech Vietnam: Your Functional Testing Partner

The reasons global companies trust AgileTech Vietnam to deliver this service, from deep expertise to uncompromising quality and security.

QA Engineers, Not Spare Developers

Functional testing is performed by engineers whose discipline is testing. Asking a developer to test their own feature produces a check of the path they built, which is a genuinely different and much narrower exercise.

We Question the Requirement First

Every engagement starts by listing the requirements that cannot be tested as written. Clients regularly tell us this phase is the most useful part, because an ambiguity found before development is cheaper than a defect found after it.

Reports Written to Be Acted On

A defect report that a developer cannot reproduce is not a finding, it is a task. Ours carry steps, environment, evidence, and the requirement breached, so the fix can begin without a second conversation.

Severity We Can Defend

We assign severity against agreed criteria and explain the reasoning. Inflating severity to force attention destroys trust in the whole report, and deflating it hides the defect that should have blocked the release.

Certified Quality Practices

Our testing runs inside a quality management system verified by ISO 9001:2015 and a security management system supported by ISO 27001:2013, which matters when testing involves access to your systems and data.

We Tell You What We Did Not Cover

Every report states the areas that were out of scope or insufficiently covered. A test summary implying total coverage is misleading, because complete coverage of a non-trivial system is not achievable and claiming it is dishonest.

10+ years operating as a software engineering company in Vietnam.
200+ talented developers and QA engineers employed in house.
300+ projects completed with 90% customer satisfaction rate.
Refined Quality Management practices verified by ISO 9001:2015
Powerful Security Management practices supported by ISO 27001:2013
Named Top App Developer in Vietnam by Clutch.co

Technologies We Work With

The languages, frameworks, and platforms our engineers rely on for functional testing.

Postman (API)

SoapUI

BrowserStack (Cross-browser)

Who can Benefit from AgileTech's Functional Testing Services?

Teams Releasing Without a Dedicated Tester

Many product teams reach a size where developers still test their own work. That works while the product is small and stops working the moment features begin to interact, because the person who wrote the code is the least able to imagine using it incorrectly.

Products Preparing for a Significant Release

A major release, a migration, or a first launch into a new market concentrates risk into a single date. The cost of a functional defect rises sharply once real users and real data are involved.

Organisations Inheriting Software They Did Not Build

When you take over a system from another vendor or through an acquisition, the documentation rarely matches the behaviour, and the people who know the difference have usually left.

Best Practices for Choosing your Functional Testing Partner

Six practical steps to evaluate and select the right partner for your project.

Ask to see a real defect report

Request a redacted example. Check whether a developer could reproduce the issue from it alone. Reports that state a symptom without steps, environment, or evidence create work rather than removing it.

Establish who designs the test cases

Ask whether cases are written from your requirements or copied from a generic template. A template pack tests a generic application, and yours is not one.

Check they push back on ambiguous requirements

A partner who accepts a vague specification without comment will test their assumption of what you meant. Ask what they do when a requirement is unclear, and be wary if the answer is that they proceed anyway.

Agree severity definitions in advance

Establish what critical, major, and minor mean for your product before testing starts. Without agreed definitions every triage meeting becomes a negotiation about labels rather than a decision about fixes.

Confirm exploratory testing is included

A plan consisting only of scripted cases will confirm the specified behaviour and miss everything else. Ask how much unscripted time is allocated and how its findings are recorded.

Clarify who owns the test assets

Test cases and regression packs are valuable artefacts. Confirm in writing that they belong to you at the end of the engagement, otherwise changing partners later means paying to rebuild them.

Flexible Engagement Models

Choose the engagement model that fits your project size, budget, and timeline. All models include dedicated communication channels and transparent progress tracking.

Frequently Asked Questions

What is the difference between functional, performance, security, and automation testing?

Functional testing asks whether the software does what was specified. Performance testing asks whether it holds up under load. Security testing asks whether it can be misused. Automation testing is not a fourth type but a delivery mechanism: it is how functional and regression checks are executed repeatedly and quickly once they are stable. Most products need functional testing first, because the other three become far more useful once correct behaviour has been established and documented.

Do you need our requirements documentation to start?

It helps, but its absence is not a blocker and is quite common. Where formal requirements do not exist we work from user stories, designs, existing behaviour, and sessions with the people who know how the product is meant to work. In that situation an early deliverable is often a written statement of expected behaviour, which the product may not have had before.

Can you test our software without access to the source code?

Yes. Functional testing is performed against the running application rather than the code, so a deployed environment and appropriate test accounts are usually sufficient. Access to the code is useful for understanding edge cases and reproducing awkward defects, but it is not required.

How many defects should we expect you to find?

We do not forecast this and we would treat any firm number as a warning sign. Defect counts depend on the maturity of the product, the quality of the requirements, and how much testing has already been done. A partner quoting an expected number before seeing the software is either guessing or planning to pad the report.

How long does a functional testing cycle take?

It depends on the size of the application, the number of user flows in scope, the clarity of the requirements, and the stability of the test environment. We scope this after reviewing the product rather than quoting a standard duration, because a figure given before that review would not be reliable enough to plan against.

Do you provide the test cases and regression pack at the end?

Yes. Test cases, the regression pack, and the coverage map are handed over and belong to you. They can be run by your own team, extended in later phases, or used as the specification for an automation suite.

Can functional testing be combined with automation?

It usually should be, in that order. Functional testing establishes which checks matter and confirms they are stable, and those are exactly the checks worth automating. Automating first tends to produce a suite that is expensive to maintain and tests the wrong things. Our automation testing service builds on the regression pack this service produces.

What engagement models do you offer for functional testing?

We work on a project basis for a defined scope such as a release cycle, and on a continuous basis where QA engineers work alongside your development team over a longer period. Which fits depends on whether you need a point-in-time assessment or an ongoing capability.

Is AgileTech Vietnam ISO certified for QA delivery?

Yes. Our quality management practices are verified by ISO 9001:2015 and our security management practices are supported by ISO 27001:2013. Both apply to testing engagements, which is relevant because testing involves access to your systems and often to production-like data.

Trusted and Recognized

Independent directories, certification bodies, and award programs that have assessed our work. Each badge links to its source or names the standard behind it, so every claim on this page can be checked at first hand.

Top Software Development Company - GoodFirms

TechBehemoths Awards - Mobile App Development

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