Granted, unit testing is a must-have. It won't however take you all the way to success. If your solution is modular in nature, or you are exposing RESTful APIs, you also need to make sure to have proper integration testing in place. About 70% of my projects involve Java development, so you might think that something like JMeter would be an obvious choice. I used to engage JMeter in the past, but when I came across Robotframework, I immediately fell in love with it. It
- is easy to install
- runs in almost any environment
- comes with ready-to-use components for a lot of use cases
- can be extended to your liking (using a number of programming languages)
- has excellent support for Python
- can be integrated in CI/CD pipelines
If you're not sure where to start exactly, you might want to consider hiring me for a seminar to get your people acquainted (I also offer my courses as webinars). If you're more the autodidact type of person, you will find lots of tutorials and getting-starteds on the web.
In the end, the key is to do integration testing after all, and the how only comes second.