Modern software is built from many moving parts. Applications connect with payment gateways, cloud platforms, internal databases, third-party services, and countless APIs. Even when individual components work perfectly on their own, problems can appear once everything is connected. That is why integration testing has become such an important part of software development. It helps teams identify issues early and ensures that systems communicate reliably under real-world conditions.

Here, you'll find integration testing companies that help businesses verify complex software ecosystems before launch. Some specialize in quality assurance and test automation, while others combine testing with broader software engineering services. Their methods may differ, but they all focus on the same challenge: making sure separate systems, services, and applications work together as expected, reducing risk and helping development teams deliver more stable software.

1. Oski Solutions

At Oski Solutions, we develop software systems where multiple applications, databases, APIs, and third-party platforms need to work together without creating operational bottlenecks. Integration testing is a regular part of our development process because modern business platforms rarely function as standalone products. We verify how different components interact across web applications, cloud environments, CMS platforms, payment systems, and business tools before they reach production environments.

In many projects, the challenge is not building a feature itself but making sure it communicates correctly with everything around it. We test integrations between CRM platforms, ERP systems, payment gateways, cloud services, and custom applications while supporting industries such as e-commerce, healthcare, fintech, education, logistics, and manufacturing. Alongside full-cycle software development, we also provide dedicated engineering teams and long-term technical support for organizations that need ongoing development and testing capabilities.

Key Highlights:

• Integration testing for custom software ecosystems

• Validation of API and third-party service connections

• Experience with CRM, ERP, and payment gateway integrations

• Support for legacy modernization and platform scaling projects

• Remote-friendly Agile development approach

Services:

• Integration testing

• Custom software development

• Web application development

• API development and integration

• Cloud solutions development

• DevOps and CI/CD implementation

• AI integration services

• CMS development with Umbraco and WordPress

Contact Information:

• Website: oski.site

• E-mail: [email protected]

• LinkedIn: www.linkedin.com/company/oski-solutions

• Address: Kaupmehe tn 7, 10114 Tallinn, Estonia

• Phone: +48571282759

2. DeviQA Solutions

DeviQA Solutions focuses entirely on software quality assurance and testing services, with integration testing forming an important part of their broader QA offering. They work with web applications, mobile products, SaaS platforms, APIs, and connected systems where multiple services need to exchange data reliably. Rather than treating integrations as isolated checkpoints, they approach testing as part of an ongoing quality process that covers functionality, performance, compatibility, and security.

A noticeable part of DeviQA Solutions' work is the combination of manual validation and automated testing. Their teams use different integration testing strategies depending on the structure of a system, including top-down, bottom-up, mixed, and big-bang approaches. They also support organizations through several engagement models, from dedicated QA teams to fully managed testing services, allowing companies to adapt testing resources as products evolve.

Key Highlights:

• Focus on quality assurance and software testing

• Integration testing for APIs, applications, and connected services

• Automated and manual testing capabilities

• Multiple integration testing strategies

Services:

• Integration testing

• Functional testing

• API testing

• End-to-end testing

• Regression testing

• Performance testing

• Security testing

Contact Information:

• Website: www.deviqa.com

• E-mail: [email protected]

• Facebook: www.facebook.com/deviQASolutions

• LinkedIn: www.linkedin.com/company/deviqa

• Address: 9 Brighton Terrace, London

• Phone: +1 805 491 9331

3. a1qa

a1qa works primarily in software testing and quality assurance, helping organizations verify that separate components within a system operate together correctly. Their integration testing services focus on checking data flow, module interactions, and software behavior after individual components have already been tested.

Their approach includes both manual and automated testing, with the testing strategy selected according to software complexity and delivery requirements. a1qa applies several integration methods, including top-down, bottom-up, hybrid, and big-bang testing. They also pay attention to regression coverage and data consistency, helping development teams identify issues before software reaches production environments.

Key Highlights:

• Dedicated focus on software quality assurance

• Automated and manual integration testing

• Data flow and interoperability validation

• Multiple integration testing methodologies

Services:

• System integration testing

• Functional integration testing

• Data integration testing

• Automated regression testing

• Test automation

• Mobile application testing

Contact Information:

• Website: www.a1qa.com

• Facebook: www.facebook.com/a1qa.software.testing

• Twitter: x.com/a1qa_testing

• LinkedIn: www.linkedin.com/company/a1qa

• Address: 160 Clairemont Ave, Suite 200, Decatur, GA 30030

• Phone: +1 720 207 5122

4. Net Devs

Net Devs develops enterprise software systems while incorporating testing activities throughout the delivery process. Their teams build applications across different technology stacks, and integration testing plays a role in verifying that services, cloud infrastructure, front-end applications, and backend systems work together as intended. Because they operate across platforms such as Azure, AWS, and GCP, testing often extends beyond a single application into broader system interactions.

What stands out about Net Devs is their combination of senior engineering oversight and AI-assisted development workflows. Testing remains under human supervision, while automation helps accelerate validation and delivery. Their work covers cloud-native systems, modern web applications, enterprise platforms, and AI-enabled products, all of which require careful verification of integrations before deployment.

Key Highlights:

• Senior engineer-led delivery teams

• Testing integrated into the development lifecycle

• Experience with cloud-native architectures

• AI-assisted engineering workflows

• Technology-agnostic development approach

Services:

• Integration testing

• Software quality assurance

• Enterprise software development

• Cloud and platform engineering

• AI engineering

• Front-end development

• Automated testing

Contact Information:

• Website: net-devs.com

• E-mail: [email protected]

• LinkedIn: www.linkedin.com/company/net-devs

• Address: Obrzeżna 1D, 02-691 Warszawa, Poland

• Phone: +48 571 282 759

5. TestFort

TestFort has been working in software testing for many years, covering integration testing alongside a broad range of quality assurance services. Their integration testing work focuses on checking how software components behave once they are connected, helping teams verify functionality, performance, security, and communication between modules before release. They test a variety of systems, including web applications, mobile products, desktop software, cloud environments, and business platforms.

The company approaches integration testing as part of a wider quality process rather than as a standalone activity. Automated testing is used where it can reduce repetitive effort and speed up validation, while manual testing helps examine areas that require closer inspection. TestFort also supports products in industries such as healthcare, fintech, retail, logistics, banking, media, and insurance, where multiple systems often need to exchange information reliably.

Key Highlights:

• Focus on software testing and quality assurance

• Integration testing for connected software modules

• Experience with cloud, desktop, web, and mobile systems

• Automated and manual testing capabilities

Services:

• Integration testing

• Functional testing

• Regression testing

• Performance testing

• Usability testing

• Compatibility testing

• User acceptance testing

• API testing

Contact Information:

• Website: testfort.com

• E-mail: [email protected]

• Twitter: x.com/Testfort_inc

• LinkedIn: www.linkedin.com/company/testfortqa

• Instagram: www.instagram.com/testfort_ua

• Address: USA, 30 N Gould St Ste R Sheridan, WY 82801

• Phone: +1 310 388 93 34

6. Mobian

Mobian develops software products and engineering teams for organizations that need reliable digital systems across mobile, AI, and backend environments. Integration testing is closely connected to their work with enterprise platforms, APIs, healthcare systems, payment flows, and legacy software. Since many of the solutions they build involve multiple technologies working together, validating those connections is part of ensuring stable delivery.

Mobian also places emphasis on maintaining existing systems while introducing new functionality, which often requires careful testing of integrations between older platforms and newly developed components. Documentation, maintainability, and long-term support remain part of their overall development approach.

Key Highlights:

• Development of mobile, AI, and enterprise software

• Experience with legacy system integration

• Dedicated teams and staff augmentation options

• Work in healthcare, fintech, logistics, and IT

• Long-term support after deployment

Services:

• Software development

• Mobile application development

• AI and automation development

• API development

• Integration testing

• Legacy system integration

• Quality assurance

Contact Information:

• Website: mobian.studio

• Email: [email protected]

• LinkedIn: www.linkedin.com/company/mobian-studio

• Address: Harju maakond, Tallinn, Kesklinna Linnaosa, Masina tn 22, 10113

7. 21Century.Tech

21Century.Tech builds software products using a combination of senior engineering oversight and AI-assisted development workflows. Integration testing forms part of their delivery process because the applications they create often connect with external services, cloud infrastructure, and third-party tools. Their process includes testing, code review, documentation, and deployment before software reaches production.

Instead of separating engineering and quality activities into different stages, they keep testing close to development throughout the project lifecycle. AI is used to assist with tasks such as generating tests and supporting implementation work, while engineers remain responsible for architecture, validation, security decisions, and final quality checks.

Key Highlights:

• AI-assisted software development workflow

• Senior engineers responsible for architecture and QA

• Human-reviewed testing process

• Support for third-party integrations

Services:

• Integration testing

• Software development

• Quality assurance

• Code review

• Third-party integration services

• CI/CD implementation

• Software refactoring

• Technical documentation

Contact Information:

• Website: 21century.tech

• E-mail: [email protected]

8. ScienceSoft

ScienceSoft provides integration testing services for organizations that need to verify how software modules, applications, and external systems interact after integration. Their testing work covers both internal connections within software and integrations with third-party platforms, helping teams identify defects that may only appear when multiple components operate together.

Their testing process includes requirements analysis, test planning, environment preparation, execution, retesting, and continuous improvement. ScienceSoft also adapts its integration testing approach to the structure of each system, using methods such as top-down, bottom-up, sandwich, and big-bang testing.

Key Highlights:

• Integration testing for internal and external system connections

• Experience with enterprise software and SaaS platforms

• Support for microservices and service-oriented architectures

• Continuous and one-time testing options

• Manual and automated testing practices

Services:

• Integration testing

• Test automation

• Continuous integration testing

• Regression testing

• Manual testing

• API testing

• Enterprise software testing

Contact Information:

• Website: www.scnsoft.com

• E-mail: [email protected]

• Facebook: www.facebook.com/sciencesoft.solutions

• Twitter: x.com/ScienceSoft

• LinkedIn: www.linkedin.com/company/sciencesoft

• Address: 5900 S. Lake Forest Drive Suite 300, McKinney, Dallas area, TX 75070

• Phone: +1 214 306 6837

9. QAwerk

QAwerk focuses on software quality assurance services and works with products that rely on multiple modules, services, and connected systems. Their integration testing activities are aimed at verifying that separate software components exchange data correctly and continue functioning as a single system after integration. Depending on the architecture and project requirements, they apply different testing approaches, including top-down, bottom-up, and big-bang methods.

The company combines manual and automated testing techniques throughout the integration process. Testing includes planning, creating test cases, executing checks after modules are connected, identifying defects, and performing retesting after fixes are introduced. QAwerk works with web, desktop, mobile, and API-based products, making integration testing part of a broader quality assurance workflow.

Key Highlights:

• Focus on software testing and QA services

• Multiple integration testing methodologies

• Manual and automated testing support

• Experience with modular software architectures

• Long-term client collaboration model

Services:

• Integration testing

• API testing

• Functional testing

• Security testing

• Usability testing

• Cross-browser testing

• System testing

• User acceptance testing

• Mobile application testing

Contact Information:

• Website: qawerk.com

• E-mail: [email protected]

• Facebook: www.facebook.com/QAwerk

• Twitter: x.com/qawerk

• LinkedIn: www.linkedin.com/company/qawerk

• Instagram: www.instagram.com/qawerk.testing

• Address: Ivana Franka St 20b, 01030, Ukraine, Kyiv

• Phone: +372 5368 6363

10. SoftPro

SoftPro develops custom software solutions for businesses that need web applications, cloud systems, and modernized digital infrastructure. Integration testing is closely related to their development work because many of the solutions they build combine frontend applications, backend services, cloud environments, databases, and third-party tools. Testing these connections helps ensure that software components exchange information correctly and continue operating as expected as systems grow.

Their technical work is centered around technologies such as .NET, .NET Core, Azure, and the Microsoft ecosystem, while also covering frontend and backend development. SoftPro supports companies through software modernization projects, cloud initiatives, and custom application development, where integration testing often becomes part of validating new functionality alongside existing business systems.

Key Highlights:

• Custom software development focus

• Experience with Microsoft technologies and Azure

• Development of cloud-based solutions

• Frontend and backend engineering capabilities

• Support for software modernization initiatives

Services:

• Software development

• Web application development

• Cloud development

• Integration testing

• Cloud migration support

• Backend development

• Frontend development

Contact Information:

• Website: soft-pro.pl

• LinkedIn: www.linkedin.com/in/kyrylo-o

• Address: Mazowieckie Voivodeship, 13 Erasmus Ciołka St. 401, Warsaw, Poland

• Phone: +48 571 282 759

11. TestMatick

TestMatick provides software testing services with integration testing aimed at verifying how different parts of an application communicate after they are connected. Their work covers API interactions, data synchronization, microservices, and cross-platform integrations, helping development teams identify issues that may not be visible when components are tested separately.

Their integration testing process includes requirement analysis, test design, execution, defect reporting, and continuous testing support. TestMatick also works with organizations that use CI/CD pipelines, where integrations need to be validated regularly as new code is introduced. They offer service virtualization for situations where dependent services are unavailable during testing.

Key Highlights:

• Integration testing for APIs, microservices, and connected applications

• Automated and manual testing approaches

• Continuous testing support for CI/CD environments

• Cross-platform integration validation

Services:

• Integration testing

• API testing

• Microservices testing

• Cross-platform testing

• Automated testing

• Manual testing

• Continuous testing

• Service virtualization

Contact Information:

• Website: testmatick.com

• E-mail: [email protected]

• Facebook: www.facebook.com/testmatick

• Twitter: x.com/testmatick

• LinkedIn: www.linkedin.com/company/testmatick

• Instagram: www.instagram.com/testmatick.team

• Address: 276 5th Ave Suite 704, New York, NY 10018

• Phone: +1 (212) 203-8264

12. A-listware

A-listware combines software development, consulting, and quality assurance services, including integration testing for business applications and enterprise systems. Their testing teams verify how software modules, APIs, databases, and external services interact, helping organizations identify communication issues before they affect production environments. Because development and testing are offered within the same delivery structure, integration validation can be coordinated alongside implementation and infrastructure work.

The company works across a wide range of business domains, including healthcare, finance, retail, logistics, manufacturing, and telecommunications. Integration testing is supported by broader expertise in cloud solutions, enterprise software, DevOps, cybersecurity, and application services. A-listware also provides dedicated teams and team augmentation services for organizations that need long-term engineering and QA support.

Key Highlights:

• Integration testing as part of broader QA services

• Collaboration with internal development teams

• Support for enterprise and business software

• Dedicated teams and staff augmentation options

• Experience across multiple regulated industries

Services:

• Integration testing

• System testing

• Test automation

• Manual QA

• Performance testing

• API validation

• Continuous integration support

• Software development

Contact Information:

• Website: a-listware.com

• E-mail: [email protected]

• Facebook: www.facebook.com/alistware

• LinkedIn: www.linkedin.com/company/a-listware

• Address: St. Leonards-On-Sea, TN37 7TA, UK

• Phone: +44 (0)142 439 01 40

13. Innovadel Technologies

Innovadel Technologies provides integration testing services for software systems that depend on APIs, microservices, cloud platforms, and third-party applications. Their testing work focuses on verifying that different components communicate correctly and continue functioning reliably when combined into a larger system.

Innovadel Technologies also offers service virtualization when connected systems are unavailable, allowing testing activities to continue without waiting for external dependencies. The company works with organizations building digital platforms that require stable interactions across web, mobile, and desktop environments.

Key Highlights:

• Custom integration testing strategies

• API and microservices testing capabilities

• Continuous integration support

• Automated and manual testing methods

• Service virtualization for dependent systems

Services:

• API testing

• Microservices testing

• Integration testing

• Cross-platform testing

• Automated testing

• Manual testing

• Continuous integration support

Contact Information:

• Website: www.innovadeltech.com

• E-mail: [email protected]

• Facebook: www.facebook.com/innovadeltech

• Twitter: x.com/innovadeltech

• LinkedIn: www.linkedin.com/company/innovadeltech

• Instagram: www.instagram.com/innovadel_technologies

• Address: 1977 North Olden Avenue #615 Ewing, New Jersey 08618

• Phone: +1 844 6964476

14. Gilzor

Gilzor develops custom digital products and includes quality assurance as part of its broader software development process. Their QA approach is built around identifying defects as early as possible, which naturally supports integration testing when applications contain multiple connected components, external services, or business workflows. Rather than leaving testing until the final stages, they combine development and validation activities throughout the project lifecycle.

The company works with web and mobile products in industries such as healthcare, fintech, education, and e-commerce. Integration testing is supported by structured processes that include requirements analysis, test planning, defect management, regression testing, and release verification. Gilzor also offers both manual and automated QA depending on the complexity of the system and the stability of the product architecture.

Key Highlights:

• Quality assurance integrated into the development process

• Shift-left testing methodology

• Manual and automated QA services

• Experience with web and mobile applications

• Work across healthcare, fintech, education, and e-commerce sectors

Services:

• Integration testing

• Quality assurance

• Regression testing

• Release testing

• Web development

• Mobile development

Contact Information:

• Website: www.gilzor.com

• E-mail: [email protected]

• LinkedIn: www.linkedin.com/company/gilzor-softwaredevelopment

• Address: Poland, Warsaw, Office 58, street Adama Mickiewicza 37, 01-625

15. KiwiQA

KiwiQA specializes in software testing and quality assurance services, with system integration testing forming part of its broader testing practice. Their work focuses on verifying how software modules, interfaces, and connected systems function together once individual components have been completed.

Their testing activities cover planning, environment preparation, test case development, automation, and continuous validation. KiwiQA also discusses several testing strategies, including risk-based testing, incremental testing, end-to-end testing, and cross-functional collaboration. The company provides testing services for industries such as banking, retail, education, media, utilities, and e-commerce.

Key Highlights:

• Dedicated software testing and QA focus

• Support for manual and automated testing

• Risk-based and incremental testing approaches

• Experience with enterprise and customer-facing applications

Services:

• Functional testing

• API testing

• Integration testing

• Performance testing

• Security testing

• Accessibility testing

• Test automation

Contact Information:

• Website: www.kiwiqa.com

• E-mail: [email protected]

• Facebook: www.facebook.com/kiwiqaservicesptyltd

• Twitter: x.com/KQSPL

• LinkedIn: www.linkedin.com/company/kiwiqa-services

• Instagram: www.instagram.com/kiwiqa_services

• Address: Suite 309, 20A Lexington Drive BellaVista NSW 2146

• Phone: +61 472 869 800

16. GigaTester

GigaTester provides software quality assurance services with integration testing designed to verify how connected systems, APIs, interfaces, and application components operate together. Their testing covers different integration methods, including big-bang, incremental, interface, scenario-based, regression, and API integration testing.

Their team supports organizations through both standalone testing engagements and longer-term QA partnerships. Integration testing is delivered alongside services such as performance, security, mobile, cloud, and SaaS testing, allowing products to be validated from multiple angles. GigaTester also works within Agile and DevOps environments where testing needs to fit into ongoing development and release cycles.

Key Highlights:

• Multiple integration testing methodologies

• API and interface testing expertise

• Support for Agile and DevOps workflows

• Dedicated QA teams available on demand

• Experience with cloud and SaaS applications

Services:

• Integration testing

• API integration testing

• Interface testing

• Scenario testing

• Regression testing

• Manual testing

• Automated testing

Contact Information:

• Website: gigatester.com

• E-mail: [email protected]

• Facebook: www.facebook.com/gigatester

• LinkedIn: www.linkedin.com/showcase/gigatester

• Address: Floor 14, Tropical Alauddin Tower, Road 2, Sector 3, Uttara, Dhaka 1230, Bangladesh

• Phone: +880 1759 747 387

17. QA Madness

QA Madness provides dedicated quality assurance services and supports companies with both manual and automated integration testing. Their work focuses on validating how separate software components function together once they are connected into a complete system.

The company offers integration testing as part of a broader QA practice that covers the entire testing lifecycle. Depending on project requirements, they combine different testing methods and levels of automation to verify functionality, reliability, compatibility, and performance across connected systems. Their services are designed for both long-term product development and ongoing software evolution.

Key Highlights:

• Dedicated focus on software testing and QA

• Manual and automated integration testing

• Testing for cloud, database, and API integrations

• Experience with enterprise and legacy systems

• ISO-certified company

Services:

• Functional testing

• Manual testing

• Automated testing

• Database integration testing

• Third-party API testing

• Payment system testing

• Integration testing

Contact Information:

• Website: www.qamadness.com

• E-mail: [email protected]

• Facebook: www.facebook.com/qa.madnesss

• Twitter: x.com/Qamadness

• LinkedIn: www.linkedin.com/company/qamadness

• Instagram: www.instagram.com/qa.madness

18. Lengreo

Lengreo is a B2B digital marketing agency that works primarily with software, technology, and IT companies. While the company appears in integration testing industry roundups, its core focus is marketing, lead generation, and business development. Their services are designed to help technology businesses improve visibility, generate qualified leads, and build predictable sales pipelines.

The company combines consulting, SEO, content marketing, outreach campaigns, and advertising to support business growth. Their work often complements software development and testing providers by helping those organizations attract clients and expand into new markets.

Key Highlights:

• Focus on B2B marketing for software and IT companies

• Lead generation and sales pipeline development

• Experience with international markets

• Multi-channel outreach campaigns

• Marketing aligned with business growth objectives

Services:

• B2B marketing strategy

• Lead generation

• Appointment setting

• SEO

• Content marketing

• Paid advertising

• Demand generation

• Website optimization

Contact Information:

• Website: lengreo.com

• E-mail: [email protected]

• Twitter: x.com/Lengreo

• LinkedIn: www.linkedin.com/company/lengreo

• Instagram: www.instagram.com/lengreo.agency

• Address: Vrijstraat 9 C/D, 5611 AT Eindhoven, Netherlands

• Phone: +31 686 147 566

19. ADeVss

ADeVss provides integration testing services as part of its broader software development and quality assurance offering. Their testing process is built around validating communication between software modules, APIs, databases, middleware, and external systems.

The company works with different application architectures, including microservices, API-driven systems, and enterprise software. Their integration testing framework includes planning, environment preparation, interface validation, API testing, end-to-end functional testing, regression testing, and continuous optimization. Testing activities are supported through a mix of manual validation and automated test execution.

Key Highlights:

• Supports microservices and API-driven architectures

• Integration testing combined with automation and regression testing

• End-to-end validation of connected systems

• Focus on interface and data-flow verification

• Covers both development and QA services

Services:

• Integration testing

• API testing

• End-to-end functional testing

• Regression testing

• Software interface testing

• Automation testing

• Custom software development

Contact Information:

• Website: www.adevss.com

• E-mail: [email protected]

• Twitter: x.com/adevss_official

• Instagram: www.instagram.com/adevss.official

• Address: 68 Willow Lane, Suite 205, Dover, DE 19901, United States

20. Trigyn

Trigyn provides functional and integration testing services within a broader quality engineering framework. Their approach focuses on validating business workflows, system interactions, and application behavior throughout the software lifecycle. Trigyn connects testing efforts with planning, coverage modeling, automation, and continuous delivery practices.

The company works with organizations that operate complex software ecosystems where functionality often spans multiple platforms, services, and external dependencies. Trigyn supports continuous testing in Agile and DevOps environments, helping teams validate integrations, APIs, data exchanges, and user journeys as systems evolve.

Key Highlights:

• Quality engineering focused approach

• Functional and integration testing services

• Support for Agile and DevOps workflows

• Continuous testing within CI/CD pipelines

Services:

• Functional testing

• Integration testing

• Test execution

• Performance engineering

• Reliability testing

• Security testing

• Compliance testing

Contact Information:

• Website: www.trigyn.com

• LinkedIn: www.linkedin.com/company/trigyn-technologies

• Address: Trigyn Technologies Schweiz GmbH, Rue de Lausanne 15, 1201 Geneve, Switzerland

• Phone: 703-454-2948

Conclusion

Choosing an integration testing company is rarely just about finding people who can run tests. The real challenge is finding a team that understands how software behaves once APIs, databases, third-party services, cloud platforms, and internal systems all start interacting with each other. Small issues at those connection points can create surprisingly large problems later, which is why many organizations invest in specialized testing support before a release reaches production.

The companies on this list take different approaches, but they share a common goal: helping teams verify that complex systems work as a complete product rather than as isolated components. Some focus entirely on quality assurance, while others combine testing with software development or consulting services. The right choice depends on your technology stack, delivery process, and business requirements, but a strong integration testing partner can make releases more predictable, reduce troubleshooting time, and help teams move forward with greater confidence.