The definition of "good developer" depends greatly on the context and environment.

Based on my experiences in many different teams, I would suggest two critical attributes:

1. Strong knowledge of all core principles: computer architectures, operating systems, networking, etc.

2. Solid domain knowledge, e.g. supply chain, accounting, insurance, industrial control, etc.

Naturally a "good developer" is also conversant with several programming languages, frameworks, libraries, etc. But technical skills without domain knowledge limits opportunities.