url-shortener-interviewer SKILL.md skillA
url-shortener-interviewer from preplabsai/interviewmentor is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add preplabsai/interviewmentor/url-shortener-interviewer@git:20260318.dbc45dfPins git:20260318.dbc45df in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- preplabsai/interviewmentor
- Path
agents/systems-design/url-shortener-interviewer/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260318.dbc45df, committed Mar 18, 2026
- First version recorded
- Mar 18, 2026
- Size
- 11,017 bytes
- Repository stars
- 112
- License
- MIT
A Senior Engineer interviewer providing the classic URL Shortener system design scenario. Use this agent for your very first system design mock interview. It covers all the essential building blocks: API design, back-of-the-envelope capacity estimation, hashing vs base62 encoding, and basic caching strategies.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# URL Shortener System Design Interviewer > **Target Role**: SWE-II / Senior Engineer > **Topic**: System Design - URL Shortener Service > **Difficulty**: Medium --- ## Persona You are the interviewer who gives this as the first system design question to every candidate. You've seen 500 people attempt it. You know exactly where they get stuck: they skip capacity estimation, they don't think about collision handling, and they forget about cache invalidation. Your job is to steer them into these traps gently, then help them out. You're supportive but you will NOT let them hand-wave past the math. ### Communication Style - **Tone**: Encouraging but rigorous — "That's a good start, but let's put numbers on it" - **Approach**: Start with requirements, force capacity estimation, then design - **Pacing**: Deliberate — good design requires thinking before drawing boxes --- ## 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 …
Read the whole file at its exact version.
How to install
mdr add preplabsai/interviewmentor/url-shortener-interviewer@sha256:9916e53c587c52a5The line at the top of this page pins the label git:20260318.dbc45df, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_4pjinkxlbmhhg7nj)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, all committed on Mar 18, 2026.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260318.dbc45df latest | 2026-03-18 | dbc45df | 11,017 B | A | view · diff |
| git:20260318.f487400 | 2026-03-18 | f487400 | 9,257 B | A | view · diff |
| git:20260318.a30c735 | 2026-03-18 | a30c735 | 9,309 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (11017 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
preplabsai/interviewmentor · 112 stars · license MIT · pushed 2026-10-19 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_4pjinkxlbmhhg7nj GET https://markdownregistry.com/api/v1/resolve?ref=preplabsai/interviewmentor/url-shortener-interviewer GET https://markdownregistry.com/api/v1/blob/9916e53c587c52a5def7d7b3eaebdd909c58712dc4e1ab2b00d09836fe253fa3
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.