Service Design · interview question

What is the healthiest performance judgment around dependency injection?

Multiple choiceMediumchapter-13-curatedpremiumservice-designdependency-injection

python

from fastapi import Depends

def get_repo() -> OrderRepository:
    return OrderRepository()

@app.get("/orders")
def list_orders(repo: OrderRepository = Depends(get_repo)) -> list[dict]:
    return repo.list_recent()

Delay clarity until production traffic reveals the edge case and then patch it under pressure.Solve the symptom with comments only and avoid changing the code shape around dependency injection.Keep dependency injection implicit so the script stays short and hope the next engineer infers the rule.Measure before optimizing, then change the part that actually dominates cost instead of guessing from style alone.

Answer and explanation

Correct answer

D. Measure before optimizing, then change the part that actually dominates cost instead of guessing from style alone.

Why

Premature optimization is usually weaker than targeted optimization backed by measurement.

Test yourself on Service Design

A free test with instant, explained results. No account needed.

Start free test

All Service Design questions →

What is the healthiest performance judgment around dependency injection?

Correct answer

Why

More Service Design questions