# Availability and consistency — System Design Interview Prep

Source: https://www.geekswithgeeks.com/en/system-design-interview/system-design-interview-11

> Use Availability and consistency to make a clear, evidence-based decision.

## Understand Availability and consistency

Start by naming the decision behind **Availability and consistency**. A strong answer explains the goal, the constraints, and the evidence you would use before acting. Do not treat a checklist as understanding: connect each step to the outcome it protects.

## Keep the workflow visible

Use this simple path while practising **Availability and consistency**: understand the situation, make one deliberate choice, then review the result.

![A four-stage workflow for Availability and consistency.](assets/figures/system-design-interview/section-3-map.svg) — Figure 3.1 — Decide, act, check and improve.

## A useful comparison

Think of **Availability and consistency** like planning a journey: a destination without a route is only a wish, while a route without a destination wastes effort.

Check the decision, not just the terminology.

**Quiz:** What is the most useful way to apply Availability and consistency?

- [x] State the goal, constraints and evidence before choosing an action.
- [ ] Copy a template without checking whether it fits.
- [ ] Use the most complex option first.

*Answer:* State the goal, constraints and evidence before choosing an action.. Good practice makes the reasoning visible, so you can review and improve it.