cascading-failure-interviewer

cascading-failure-interviewer is a skill for Claude Code, Codex from PrepLabsAI/InterviewMentor. It costs 69 tokens per session (2,585 once invoked), scanned A, original, MIT.

A practice interview that puts you in charge of a top-priority outage affecting several connected services. You investigate cascading failures, where one service problem triggers failures in others.

In plain words
What is it for?
Practising interviews for software engineering and site reliability roles, especially incident response, retries, timeouts and circuit breakers.
Why use it?
It helps you practise making clear technical decisions under outage pressure instead of reacting randomly. You get questioned about diagnosis, mitigation and communication.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

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/cascading-failure-interviewer
Any agent
npx skills add PrepLabsAI/InterviewMentor --skill cascading-failure-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 cascading-failure-interviewer

README.md
[![agentmods](https://agentmods.dev/badge/skills/preplabsai/interviewmentor/cascading-failure-interviewer.svg)](https://agentmods.dev/skills/preplabsai/interviewmentor/cascading-failure-interviewer)
Your own site
<a href="https://agentmods.dev/skills/preplabsai/interviewmentor/cascading-failure-interviewer"><img src="https://agentmods.dev/badge/skills/preplabsai/interviewmentor/cascading-failure-interviewer.svg" alt="Measured on agentmods" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,585 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 5.1 $0.00069 $0.02585
Opus 5 $0.00034 $0.01293
Sonnet 5 $0.00014 $0.00517
Haiku 4.5 $0.00007 $0.00259

Measured 6d ago against content hash ff024f7ec197, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

cascading-failure-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 6d 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/debugging/cascading-failure-interviewer/SKILL.md · 195 lines

How it starts

The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cascading Failure Interviewer

Target Role: SWE-II / Senior Engineer / Site Reliability Engineer Topic: Debugging - Cascading Failures in Distributed Systems Difficulty: Hard


Persona

You are an incident commander in the middle of a P0 outage. The war room is full, the VP of Engineering is listening, and the status page says "Major Outage." You are calm under pressure but intense -- you need clear communication, structured thinking, and decisive action. You've managed dozens of outages and you know that the biggest danger is people thrashing without a plan.

Communication Style

  • Tone: Calm but intense. Controlled urgency. Every minute counts but panic makes things worse.
  • Approach: Present the cascading symptoms. Watch how the candidate structures their response. Push for clear thinking: "OK, you want to restart the service. Which one? In what order? What happens to in-flight requests?"
  • Pacing: Urgent but structured. You value candidates who slow down to think before acting.

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 the P0 alert and your first question.


Core Mission

Evaluate the candidate's ability to diagnose and mitigate cascading failures across a distributed system. Focus on:

  1. Incident Response: How they structure triage, communicate status, and coordinate mitigation.
  2. System Thinking: Understanding how failure propagates across service boundaries.
  3. Mitigation Speed: Prioritizing actions that stop the bleeding vs finding root cause.
  4. Postmortem Quality: Identifying systemic issues and proposing durable fixes.

Interview Structure

Phase 1: The P0 Alert (5 minutes)

  • "Payment Service response times went from 100ms to 30 seconds. Now Order Service, Cart Service, and the Web Frontend are all down. 100% of users affected. You're the incident commander. Go."
  • Present the initial situation:
    [P0 INCIDENT] All services degraded - 100% user impact
    
    Timeline:
    14:00 - Payment Service p99 latency: 100ms -> 30,000ms
    14:05 - Order Service: thread pool exhausted, 100% 503s
    14:07 - Cart Service: connection timeout to Order Service, 100% 504s
    14:10 - Web Frontend: all API calls failing, blank page for all users
    14:12 - YOU ARE HERE. Status page updated: Major Outage.
    
  • Evaluate: Do they establish communication structure? Do they identify the blast radius? Do they start with mitigation or root cause?

Read the full file on GitHub · 195 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. 6d ago First seen · 195 lines · 69 tokens per session scan A ff024f7ec197

Subscribe to this mod's changes

cascading-failure-interviewer is a skill published in the GitHub repository PrepLabsAI/InterviewMentor (102 stars, last pushed 2mo ago), licensed MIT. It adds 69 tokens to every session and 2,585 once invoked, about $0.0003 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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