Principles I Strongly Believe In
No matter what context or which device, the user should always get the best experience possible. Usability and visibility are the factors of success and web-standards-based HTML is the foundation. I actually do read W3C and WHATWG specifications.
Definition of maintainability: How easy is it to safely make changes to the code? In development, there is nothing I care more about than maintainability. Even above and beyond correctness. I believe in pattern libraries, up to date documentation, linting rules and automated testing.
Performance is Design
The performance budget should be defined as early as possible in a project. Because performance is the responsibility of the entire team from concept to design to development. The Speed Index is one of the most interesting indicators for measuring performance.
Communication is Key
All good principles and techniques are worthless if the right people do not talk to each other at the right time. Having regular open and honest conversations is key to the success of a project. Agile methodologies like Scrum are an effective approach to manage communication.