Recently, an admin asked me if we are doing microservices.

I thought about it for a few moments. And what I said comes here as a checklist.
It’s a really simple test with quick yes or no.

Single Responsibility Principle
Is your service small and focused on doing one thing well?

Domain-Driven Design
Is your service modeled around business concepts?

Technology Heterogeneity
Are you free to pick technology, tool, language, framework or what ever for your service?

Interface
Has your service an explicitly published interface and
are internal implementation details are hidden?

Autonomous
Can you make a change to a service without changing anything else?

Independently deployments
Requires a deployment of your service coordination with other teams?

Scaling
Can you scale your service independently via cloning or sharding?

Resilence
Does your service can take corrective actions automatically?

Fault and resource isolation
Will affect a memory leak or an unclosed database connection only your service?

Lightweight Communication
Do you use REST or other lightweight communication protocols?