Technical University in Gabrovo, Bulgaria is celebrating 60 years anniversary in July this year. Our department – Computer Systems and Technologies is part of the Faculty of Electrical Engineering and Electronics and it teaches students in computer-oriented disciplines.

During the COVID-19 crisis, the need for effective e-learning environment was realized. Since we were unprepared, we needed to apply the trial-and-error approach. We started to try different tools and environments for distance learning for our students. We passed through many iterations, until we reached the current situation – to build a stable and functional environment for e-learning.

Initially the following components of the system were defined:
1. E-learning platform, which must have the following features:
- Uploading of static and dynamic materials, including files, videos, etc. and the possibility for restricted access to these materials;
- Communication between teacher and students – online and offline. Online communication includes streaming of video, audio and presentation, offline communication includes exchange of text messages and files;
- Ability to connect to the video lecture through any device – including smartphone, tablet, desktop PC etc.;
- Ability to connect many users simultaneously.
We tried many different platforms and finally we implemented a set of tools to establish our goals.
We created a specialized platform for upload and store the video lectures in a structured approach.

2. A platform for distance laboratory exercises in computer oriented disciplines:
This was a huge challenge, because in these disciplines the students often need to install and configure operating systems, application software to create databases and to configure computer networks. To allow these features we created a specialized platform for performing laboratory exercises using virtual machines.

3. Examination platform:
Distance examination also proved to be a significant problem. Since modern students know how to share information quickly with each other via different electronic channels, it is very difficult to determine the real knowledge of all students with a static test. In addition, with traditional electronic tests, there is no reliable way to determine the student's identity, and it is not always clear who exactly is taking the test. Therefore, traditional testing methods must be enhanced with opportunities to ask personalized questions, dynamically adjust tests based on previous answers, and opportunities to implement creative solutions to problems in electronic tests.
In our platform, we combined the traditional tests with a dynamic skills-based assessment.

Unfortunately with the start of ChatGPT, we realized that the answers of our students, especially for the questions that needs an answer to be entered manually by the students, most of the answers are generated by the AI. We are still working and improving in the attempts to limit the usage of AI engines for answering the questions.

The aim of this paper is to share our experience, starting from defining the initial need for e-learning system, to describe some technical details, encountered difficulties and the way we overcome it, as well as the overall effect from implementation of the system.

Keywords: e-learning, distance education, online lectures, laboratory exercises, examination.