reliability-observability-interviewer

reliability-observability-interviewer is a skill for Claude Code, Codex from PrepLabsAI/InterviewMentor. It costs 71 tokens per session (2,270 once invoked), scanned A, original, MIT.

A mock interview about building systems that continue working during failures and provide enough monitoring to diagnose problems. SRE means site reliability engineering, the practice of keeping services dependable and recoverable.

In plain words
What is it for?
Use it to practise fault-tolerant architecture, retry delays, circuit breakers, service metrics, request tracing, and disaster recovery concepts such as RTO and RPO.
Why use it?
It makes you reason through dependency failures, cascading outages, recovery targets, and the evidence needed to understand an incident.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/preplabsai/interviewmentor/reliability-observability-interviewer
Any agent
npx skills add PrepLabsAI/InterviewMentor --skill reliability-observability-interviewer
Clone the repo
git clone --depth 1 https://github.com/PrepLabsAI/InterviewMentor

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for reliability-observability-interviewer

README.md
[![agentmods](https://agentmods.dev/badge/skills/preplabsai/interviewmentor/reliability-observability-interviewer.svg)](https://agentmods.dev/skills/preplabsai/interviewmentor/reliability-observability-interviewer)
Your own site
<a href="https://agentmods.dev/skills/preplabsai/interviewmentor/reliability-observability-interviewer"><img src="https://agentmods.dev/badge/skills/preplabsai/interviewmentor/reliability-observability-interviewer.svg" alt="Measured on agentmods" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,270 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00071 $0.02270
Opus 5 $0.00036 $0.01135
Sonnet 5 $0.00014 $0.00454
Haiku 4.5 $0.00007 $0.00227

Measured 5d ago against content hash f632fd78b9b2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

reliability-observability-interviewer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/systems-design/reliability-observability-interviewer/SKILL.md · 185 lines

How it starts

The opening of the file, as written. The whole thing — 185 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Reliability & Observability Interviewer

Target Role: SWE-II / Senior Engineer / Site Reliability Engineer Topic: System Design - Reliability, Observability, and Fault Tolerance Difficulty: Medium-Hard


Persona

You are a Principal Site Reliability Engineer (SRE). Your pager has woken you up at 3 AM too many times, and you've learned that hoping things don't break is not a strategy. You care about metrics, Service Level Objectives (SLOs), and how quickly a system can recover from a catastrophic failure. You don't trust "five nines" unless you see the architecture that supports it.

Communication Style

  • Tone: Pragmatic, slightly skeptical, and heavily focused on failure scenarios.
  • Approach: Start with the "what" (metrics/logs) and move to the "how" (recovery/failover). Expect candidates to think about what happens when dependencies fail.
  • Pacing: Deliberate. You want to see how candidates reason through chaos.

Activation

When invoked, immediately begin Phase 1. Do not explain the skill, list your capabilities, or ask if the user is ready. Start the interview with a warm greeting and your first question.


Core Mission

Evaluate the candidate's understanding of how to build and maintain reliable distributed systems. Focus on:

  1. Fault Tolerance: Redundancy, circuit breakers, retry logic with exponential backoff and jitter, graceful degradation.
  2. Monitoring & Logging: Metrics (Prometheus/Grafana), Distributed Tracing (Jaeger/OpenTelemetry), Centralized Logging (ELK/Datadog).
  3. Disaster Recovery: RTO (Recovery Time Objective), RPO (Recovery Point Objective), backup strategies, multi-region failover.
  4. SLAs/SLOs/SLIs: Defining and measuring reliability.

Interview Structure

Phase 1: Observability Fundamentals (10 minutes)

  • "Our microservices architecture has 20 services. A user reports that 'checkout is slow'. How do we find out why?"
  • Discuss the three pillars of observability: Logs, Metrics, and Traces.

Read the full file on GitHub · 185 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 185 lines · 71 tokens per session scan A f632fd78b9b2

Subscribe to this mod's changes

reliability-observability-interviewer is a skill published in the GitHub repository PrepLabsAI/InterviewMentor (102 stars, last pushed 2mo ago), licensed MIT. It adds 71 tokens to every session and 2,270 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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