1) No way. Absolutely not. Not if what you're building is intended to last. Any language/ecosystem you choose has costs and benefits. You will continue to pay t

1) No way. Absolutely not. Not if what you're building is intended to last. Any language/ecosystem you choose has costs and benefits. You will continue to pay the costs (and reap the benefits) long after your developers could have become fluent in a language. Certainly the language your developers already know is better than one they don't, all things being equal. But your rule is way too simplistic. 2) Of course. Avoid every complex thing where possible. 3) This means the cost/benefit ratio was not considered closely enough when planning these features. Again, avoid every complex thing where possible. 4) this is a strange one. Most people doing CI are not building microservices. CI is really more about whether you have different, independently moving pieces that need to by integrated. Could be microservices, could be libraries, could be hardware vs software. If you only have a single active branch everyone's merging into regularly, you're doing CI implicitly. You just might not need it automated. 5) take what you can from the wisdom of agile, and then use your own brain to think. And don't confuse agile with scrum.