API Testing

with technical approach, using Postman, SoapUI and Tosca.

For over 15 years, Soflab has been helping companies by optimizing the software testing process. Well-prepared and conducted tests allow to reduce the risk which enables companies to become an industry leader.

Gain Profits

  • By drawing special attention to API tests, you reduce the number of manual tests required. It can save a lot of time for your company thou the quality assurance process become more effective.
  • Emphasizing on technical approach allow to detect defects earlier and more efficient which optimize testing costs and improve the quality of the software at the same time.
  • By investing in APi integration tests you open up for automation which can lead to constant quality monitoring. Automation can make your business processes across diverse applications and technologies more reliable.

 API Testing Benefits

Optimize testing time

Early defect detection

Reduce test costs

Automation enabled

Stress and Performance testing

Uncover security gaps

Why Testing API with Soflab?

  • Experience – over 15 years in software testing service.
  • 200+ testing professionals and experts
  • Practice based original methodology in line with international standards such as ISO and ISTQB.
  • Proficiency in tools such as Postman, SoapUI, Apache JMeter, Cypress, Selenium, Tosca, etc.
  • Range of projects across a variety of sectors, including telecommunication, finance, insurance, media, energy, and public administration.
  • Soflab assure quality for CEZ products providing confidence in e-prescriptions, e-referrals and IKP (online patient account).

Types of API Testing Soflab Performs

Automated API testing – DevOps pipeline integration

Frequently repeated manual tests can be automated. It can save a lot of time by shortening the quality assurance process. However, this is not the only advantage of automation. Automated tests can be performed remotely, and the time of their launch can be set to any time. In addition, automatic tests drop the risk of making mistakes because of routine or fatigue. However, their biggest advantage is compliance with the practice and philosophy of DevOps CI / CD (Continuous integration / Continuous delivery or deployment). When API automated test scripts are attached to a continuous integration server, they become regression tests.


API performance testing

API performance tests consist of creating a load and checking the system in terms of response time and resource consumption. Manual execution of this type of tests is exceedingly difficult or even impossible. Therefore, in this case, automated tests are most often conducted. Performance tests using APIs are one of the simpler methods that does not require specialized “frameworks” and writing advanced scripts.

API security testing

Security tests are designed to uncover vulnerabilities identify threats and security gaps. Authorized and fully controlled security breach attempts reveal non-attack resistant spots. The study covers such areas as:

  1. user authorization,
  2. access control,
  3. roles and permissions.

A critical issue is the verification of safety already at the early stage of production, planned at the level of unit, integration, and system tests. Taking this type of action increases the effectiveness of the tests conducted.

API integration testing

Integration testing is designed to confirm communication between components. They are performed at the message layer of the app so it can be implemented on early stage of software development. Usually, at this stage, it is not possible to perform tests using the GUI, which may not be ready yet. Testing API integration is the most used method by experienced test teams.

API Testing Plan

  • System architecture and specification, data model and API message format study
  • Designing the test strategy and test plan document – list of endpoints and verification overview
  • Selecting the relevant testing tools suitable for client’s project
  • Setting up testing environment and configure the testing tools
  • Test data preparation – volume, formats and structure
  • Sending a number of requests for verifiing communication between endpoints
  • Test Summary Report


  Why API Testing is Required?

Executing API tests is possible at a very early stage of software development life cycle. Testers can verify modules on the message layer of the app. That approach allow teams to find and fix bugs earlier which saves time and reduce costs. As a result, the software development process becomes more efficient and the total time needed to deliver the completed product or functionality is shortened.

In Agile methodologies api testing become even more important thou testers are the part of developers team. Moreover, this approach enable automation which can be a part of CI/CD – automated software release process. Via API you can also conduct performance testing.

What is “Shift-Left” Testing? 

It is well known that more costly to discover and fix a defect later in the process. According to Tatyana Sidorova from ScienceSoft “…nearly 60% of all software defects emerge during the requirements phase, about 30% – during the design phase, and only 10% – during development”. Therefore this is reasonable to put QA activities closer to the begining of the delivery pipeline by “shifting them to the left”. API testing perfectly fits this idea.

However, this requires technical competencies and skills that business teams usually do not have. These are much more complex tests than regular UAT tests performed on the client’s side. The conduct of manual technical tests requires knowledge of the appropriate test tools. Therefore, it is necessary to employ experienced and qualified testers.


Soflab Technology provides full-range API testing services to help our customers take shift left approach.

Why Soflab?

know-how na podstawie wielu projektów w różnych branżach

zespół kompetentnych ekspertów

gotowe, sprawdzone, oparte na praktyce procedury testowania

doświadczenie i dobór odpowiednich technologii i narzędzi

autorska metodyka testów Soflab Test Approach

własny Testlab urządzeń do testów aplikacji mobilnych



ul. Ligocka 103
40-568 Katowice
Bookkeeping: +48 32 353 31 25
Fax: +48 32 353 31 26


Al. Jerozolimskie 123a (Atlas Tower)
02-017 Warszawa
Sales Department: +48 22 122 82 43
Marketing: +48 22 122 84 96
Administration & HR: +48 22 122 82 26


ul. Wagonowa 2
53-609 Wrocław
Phone: +48 500 000 229

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