1 min lesson
Service contracts & abstractions
Name the parts in "Service contracts & abstractions" and give the practical job of each one.
Step 1 of 3
Core Services sits between every product surface and the infrastructure underneath. The contracts you draw there are impact: a good one unblocks every product team at once, a leaky one creates coordination tax forever.
The JD calls for "clean abstractions, well-defined service contracts." In the interview that means you can name what each service promises, version those promises without breaking callers and defend where you drew each line.