- Programming Language (PHP, JavaScript, Python) - RDBMS (MySQL, SQLite) - NoSQL (MongoDB, Redis) - Specialised searching ( Elasticsearch, Apache Solr) - Javascript Frameworks (jQuery, React, Backbone, Marionette, Angular) - MVC frameworks (Laravel, Symfony2, Zend Framework 1/2, Kohana, CodeIgniter, Flask) - CMS (Wordpress, Drupal) - Distributed job queue system (RabbitMQ, Gearman, SQS) - Different levels of caching (Memcached, Redis, Varnish) - API integration (REST, SOAP, XML-RPC) - Web server (Nginx, Apache) - AWS (VPC, EC2, ELB, S3, Lambda, SQS, SNS, CloudFront, CloudWatch, Auto-Scaling etc )