Version Control System

# VCS Level
1 Git
2 SVN

Programming Language

# Programming Language First "Hello World!" Level
1 Java 2011
2 C 2011
3 C++ 2011
4 C# 2013
5 Groovy 2017
6 javascript / nodejs 2018
7 Python 2018
8 Ruby 2018

Tech Stack / Framework

# Framework First "Hello World!" Level
1 Android-Java 2013
2 Spring 3,4 2015
3 Spring Boot 2017
4 C# 2013
5 Groovy 2017
6 javascript / nodejs 2018
7 Python 2018
8 Ruby 2018

Other Tech Stack

# Software Level
1 Tomcat
2 Jetty
3 Apache httpd
4 Nginx
5 Hibernate
6 MyBatis
7 Zkoss
8 Jasper Report

Databases & Messaging


SQL

# Databases Level
1 MySQL / MariaDB
2 Oracle
3 SQL Server
4 Postgres

NOSQL

# Databases Level
1 MongoDB
2 Cassandra

Messaging & Queue

# Databases Level
1 Redis
2 RabitMQ
3 Apache Kafka