1. Back-end
2. Front-end
3. App (Android)
4. System Design
5. Project Lead
6. IT

SAP, AWS, Automation, AI - since 2023
Python, PostgreSQL - since 2022
PHP, MySQL - 2015-2022
Javascript, Jquery - since 2015
HTML, CSS - since 2014 or earlier

Java (Android app) - 1 year
Web design - since 2014

// Update: 2019-09-11
// Last update: 2025-07-11