These qualities help to achieve you a prospective testing career. Some qualities apply to manual testers and some apply to automation testers.But in general characteristics of a good tester are below :
Testing sense is the foremost quality a tester should have. Testing sense , attitude to “break software” .In addition , a good tester should have passion to break software.
Good Communication Skills
Good communication both written and verbal is essential for a good tester.In addition to,hard skills, soft skills also are must for a good tester . Tester should write up bug reports that are easily understood across the organization. Soft skills for QA meetings , negotiations , scrum meetings and bug triage meetings.
Learn New things
This is another interesting quality of a tester.Good tester should have ability to learn new things quickly.
End User Perspective
A good tester should have innovation and ability to think like an end-user of the product .Products and features are developed for end -users. Tester should think like an end user. This reduces defect escape.
Tester should have positive outlook and respect in the organization. Testing is a destructive activity to make the product constructive and improve quality of the product.
Bashing developers is a major pastime of some testers after logging the defect. Since developers have a different job. Being negative only creates friction and doesn’t help improve overall quality of the product.
Tester should have patience . Since during testing cycles and regression testing testers may need to repeat the same things or test steps.Therefore, having patience is a good quality for a tester.
Essential programmatic knowledge and skill is a must for automation tester. Also, automation testers develop automation tests using different automation tools in languages like Java , C# , C++, Python etc. Furthermore, the line between the developer role and tester role becomes thin in Agile environment. Some organizations and startups might expect aggressiveness and ability to “fix things” from a tester .
Statistics and Mathematics
Essential knowledge on Statistics and Mathematics is a must for Performance/Capacity testers .For example : understanding average and mean response times.Consequently, having knowledge in Stats would help understanding the percentile number of requests pass the SLA , graphs during load , capacity and spike tests etc.
Ability to ask different questions
In addition testers should have ability to ask questions. A good tester never assumes things and asks questions.Asking questions can benefit to get the big picture of testing.
Being realistic and optimistic
Rather being negative, tester should be realistic and optimistic.Tester should be realistic about what developers and other players in the process can achieve.
Another important quality is being agile .Characteristic of tester especially when working under a scrum team in agile environment.