Frontend 

Angular 2+, TypeScript, SASS, LESS, HTML5, CSS3, jQuery, React 

Cloud Services 

AWS EC2, S3, CloudFront, Lambda 

Programming Language 

JavaScript, Ruby, Python, Go 

DevOps tools 

Chef, Docker, Jenkins, Ansible 

SQL Databases 

MySQL, PostgreSQL 

NoSQL Databases 

MongoDB 

Web Frameworks 

Rails, Django 

Operating Systems 

Ubuntu 12.04+, CentOS 6-7, MacOS, FreeBSD, Windows 10, Window Server 2016 

Testing Frameworks 

Jasmine, Protractor, Karma, Minitest, RSpec