If you want to develop complex solutions that are robust and scalable you need something to process and save all your data before reaching the UI. 

Previously I've worked with AGILE and Waterfall - both have pros and cons

My language of choice is Java, backed by Spring Framework which makes me deliver modules in a 

stellar way.

My promises: 

 - The code will be unit tested so that if somebody else joins he can make changes comfortable without breaking unknown things

 - The modules will be documented

 - The deployment procedure will be documented

 - I will host it in the cloud of your choice

 - We will have regular demos in order to have a sense of how far along we are.