All listed below tech specs are for those who understand theme. As for business people I just would like to say that I share such an opinion that any program I write is requested due to a profit. So commercial success of my code – is general approach. I do realize that all listed below details means nothing if my result does not bring commercial benefits to customer.
I have a big background in PHP coding, especially in Zend Framework (but other frameworks and pure PHP are well known too). Node.js from year to year becomes more common for me as well.
MySQL, PostgreSQL are being used for database engine including such a sharp tools as foreign keys, stored procedures and triggers. MongoDB, Redis are well known too. Normalize and denormalize DB structure ideas to speed up DB engine reply are familiar for me. Triggers, stored procedures, transactions, foreign key restrictions – are features I used to apply in some of my projects.
My most favorite is AngularJS.
On server side also Memcached and Sphinx could be used by me to boost server response time.
In addition I am Linux and MacOS user. Bash and cron scripting, logs analysis, SSH connection, LAMP and etc. are well known and pretty often being in use.
Of course I use Git for code versions tracking (SVN is okay as well). Recently I started to use Grunt for building releases.