Živan Šinžar


Živan is a senior test engineer with 10 years of general QA experience, currently working for Endava. His focus has been on team leadership and backend automation for RESTful web services in recent projects. He has gained experience by taking on different roles in development teams he has been a part of. He started with manual test execution, which quickly evolved into a business analysis role. The client recognized his ability to understand business needs and translate them into testing scenarios. To expand his knowledge and skills in technical positions, he took on roles involving frontend automation, backend automation, and performance testing. As he gained more experience, opportunities for team leadership opened up, but he always insisted on positions that required hands-on technical work as well. Recently, one of his projects required an ad-hoc solution to a resilience testing problem. By tackling the issues on that project, he gained valuable experience that he felt could be shared at the Hustef conference. Most of his experience is related to online market trading and online payment processing areas. The projects he has been a part of received great feedback from clients. Praises from these feedbacks were mostly attributed to the teams as a whole, highlighting the collaborative effort rather than individual contributions. He has always emphasized that goals cannot be achieved in isolation; teamwork is crucial. He consistently puts in extra effort to foster a high team spirit, recognizing it as an essential aspect of a successful team. He enjoys sharing his experiences and knowledge gained from handling day-to-day issues. Additionally, he values listening to others' struggles, as he believes that being a good listener and willing to try proposed solutions accelerates learning more than experiencing struggles alone. Currently residing in Belgrade, Serbia, father of a beautiful daughter named Žana and is expecting his firstborn son just before the Hustef 2023 conference.

About the Presentation

Resilience testing in modernization projects 
Session Speech


Based on my experience, when companies are migrating their existing architecture into microservice one, from testing point of view functional requirements are usually there and from non-functional side focus is mostly on performance metrics defined for an old architecture. If we’re lucky we also have some new performance metrics defined with other non-functional aspect usually ignored.

Resilience requirements are often left to be dealt just before going live, by a separate team or a few experienced individuals with little to no time left for improvement if something suspicious is noticed.

In this presentation, I would like to share our experience with tackling some of the challenges, while working with a large corporation (payment domain, where stable environment is crucial to business success as even a small error can lead to great penalties), that selected our company as a partner in modernization.

I will present concepts and questions that each delivery team needs to ask as early as possible, preferably in design phase, to be able to have resilient service from a get go:

  • How to test service discovery (on-prem vs cloud)
  • How to test logs (coverage and usefulness)
  • How to test service and business flow resilience aspects:
  • Retry and timeout logic
  • Failover and grace period logic
  • Connection pool config
  • What specific scenarios should be included:
  • Dropped connection, Garbled response
  • Random data, Empty responses, Unexpected or missing fields
  • Large payloads, Special characters…
  • How to learn quickly about an unknown complex system:
  • Mocks and proxies
  • Service Mesh