Too many things to mention here. Stop using the shiniest tools and tech, go for sturdy industry standards, we're not building rockets here, start caring about processes and stop ignoring QA. Your velocity gets you nowhere with such an execution.
The person who singlehandedly decided to rewrite the entire application (without any dire need for that) in the worst combination of language and framework possible was promoted to team lead. That is pretty descriptive of the management and some people in the team who support him.