Bite by bite. Use the facade pattern, implement the new features cleanly outside of it, and when times allow, refactor and extract modules cleaning them; until

Bite by bite. Use the facade pattern, implement the new features cleanly outside of it, and when times allow, refactor and extract modules cleaning them; until nothing's left behind the facade. http://jargon.js.org/_glossary/FACADE_PATTERN.md http://jargon.js.org/_glossary/FACADE_PATTERN.md