✦ Free sample scenario · No account needed

Setting SLOs for a brand new service — no history, no data

Beginner≈ 12 minSlo MonitoringObservability Engineering

Production Context

Your team has just launched a new order confirmation service. It has been live for 3 days. The product manager asks you to set SLOs before the next sprint. There is no historical data. No SLIs have been defined. No one has agreed on what "reliable" means for this service. The service handles order confirmations — a user submits an order and expects a confirmation within 3 seconds.

Days Live

no baseline data yet

Error Rate

Unknown

not yet measured

User Journey

Submit → Confirm

< 3s expected

What is the difference between an SLI and an SLO?

Which of these would be valid SLIs for the order confirmation service? Select all that apply.

Percentage of order confirmation requests that return a successful response

Percentage of order confirmations delivered within 3 seconds

CPU utilisation of the confirmation service pods

Percentage of users who receive a confirmation without needing to retry

Number of database connections open at peak

You have no historical data. What is the best approach to set your first SLO target?

Set it at 99.99% — always aim for the highest reliability possible.

Wait 30 days, measure actual performance, then set the target based on observed data.

Set a conservative starting target (e.g. 99%) based on user expectations, then tighten it after measuring actual performance.

Which of these are good principles when designing your first SLO? Select all that apply.

Choose SLIs that directly reflect whether the user got what they needed

Set the SLO target as high as possible to show ambition

Start with one SLI per critical user journey

Make the target achievable — slightly below your actual measured performance

Add as many SLIs as possible to maximise coverage from day one

If your SLO is 99% over 30 days, how much downtime does your error budget allow?

1 hour

7.2 hours

14.4 hours

Write a complete SLO statement for the order confirmation service.

Example: "99% of order confirmation requests will return a successful response within 3 seconds, measured over a rolling 30-day window."

lock

5 more tasks in this scenario

Create a free account to finish this scenario, get scored feedback on every answer, and track your confidence across all 61 scenarios.

Free to start · No credit card required

Already have an account? Sign in

Why SLO design is an interview-critical skill

Almost every Japan SRE job posting lists SLO/SLI work explicitly — PayPay, Money Forward, TEKsystems all require it. Being able to define SLOs from scratch, explain the difference between SLI and SLO, and calculate error budgets is table-stakes for senior SRE interviews.

Skill Map

2 domains

SLO Monitoring

Define SLIs and SLOs for a service with no historical data.

Observability Engineering

Choose the right signals to measure user experience.

Guided Help

Non-dev SREs

Practice all 61 scenarios

Nine SRE skill areas, scored feedback on every answer, and a readiness score that reflects where you actually stand.

Create free account →