I've canceled my job to move on. Now I was asked how I want my Job description for my employment reference.

My first draft was one full page... This is too much. Now I've reduced the long version to a short version with 4 bullet points. But I'm not happy with this version. I've read lots of things about the usage of active verbs etc pp. But on the other hand, there are a lot of sites which say to use nominalization. I'm confused and want to use the possibility to write my job description. Originally it is written in german. That's why I try to translate it as true to original.

* Development and architecture of APIs, web services, websites and services with .net Core 2.x and C#
* Architecture and implementation of cloud reorientation with Google Kubernetes & Docker
* Automation of the development and deployment process with GitLab and Helm
* Analysis and optimization of existing interfaces

The last sentence sounds like one, which could be used for every employee. But I want one sentence which describes my possibility to work in existing code.