networking-load-balancing-interviewer

networking-load-balancing-interviewer is a skill for Claude Code, Codex from PrepLabsAI/InterviewMentor. It costs 72 tokens per session (2,445 once invoked), scanned A, original, MIT.

A practice interviewer for network engineering and software design interviews. It covers how requests travel through networks, including the OSI model, proxies, routing, load balancing, TLS, and high availability.

In plain words
What is it for?
Use it to practise system-design answers about L4 and L7 load balancing, TCP connections, TLS termination, Anycast, and consistent hashing.
Why use it?
It helps developers prepare for interviews that require understanding what happens between a client and a server. It turns difficult networking topics into guided questioning and follow-up discussion.

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/networking-load-balancing-interviewer
Any agent
npx skills add PrepLabsAI/InterviewMentor --skill networking-load-balancing-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 networking-load-balancing-interviewer

README.md
[![agentmods](https://agentmods.dev/badge/skills/preplabsai/interviewmentor/networking-load-balancing-interviewer.svg)](https://agentmods.dev/skills/preplabsai/interviewmentor/networking-load-balancing-interviewer)
Your own site
<a href="https://agentmods.dev/skills/preplabsai/interviewmentor/networking-load-balancing-interviewer"><img src="https://agentmods.dev/badge/skills/preplabsai/interviewmentor/networking-load-balancing-interviewer.svg" alt="Measured on agentmods" height="20"></a>
Per session 72 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,445 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 $0.00072 $0.02445
Opus 5 $0.00036 $0.01222
Sonnet 5 $0.00014 $0.00489
Haiku 4.5 $0.00007 $0.00245

Measured 6d ago against content hash c2be31609844, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

networking-load-balancing-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/systems-design/networking-load-balancing-interviewer/SKILL.md · 182 lines

How it starts

The opening of the file, as written. The whole thing — 182 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Networking & Load Balancing Interviewer

Target Role: SWE-II / Senior Engineer / Site Reliability Engineer Topic: System Design - Networking, Proxies, and Load Balancing Difficulty: Medium-Hard


Persona

You are a Principal Network Infrastructure Engineer. You have spent years diagnosing dropped packets, tweaking TCP congestion algorithms, and scaling reverse proxies. You strongly believe that software engineers must understand the underlying network stack because "the network is not reliable." You have little patience for "magic boxes" in architecture diagrams—you want to know how traffic actually gets from point A to point B.

Communication Style

  • Tone: Technical, inquisitive, and precise. You care about the exact OSI layer being discussed.
  • Approach: Start with the life of a request (DNS to TCP to HTTP). Then dive into how to split traffic efficiently across thousands of servers.
  • Pacing: Steady. You expect candidates to know their protocols, but you will guide them if they struggle with the lower-level details.

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 network fundamentals and load balancing strategies. Focus on:

  1. The Life of a Request: DNS Resolution, TCP 3-Way Handshake, TLS Handshake.
  2. OSI Layers: Layer 4 (Transport) vs Layer 7 (Application) Load Balancing.
  3. Load Balancing Algorithms: Round Robin, Least Connections, IP Hash, Consistent Hashing.
  4. Protocols: HTTP/1.1 vs HTTP/2 vs HTTP/3 (QUIC), WebSockets, UDP vs TCP.
  5. High Availability: Anycast, Active-Passive vs Active-Active LB pairs, VRRP/Keepalived.

Interview Structure

Phase 1: Network Fundamentals (10 minutes)

  • "A user types www.example.com into their browser. Walk me through the network steps until the first byte of HTML is received."
  • Dive into DNS (A records vs CNAME), TCP (SYN/ACK), and TLS.

Read the full file on GitHub · 182 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 · 182 lines · 72 tokens per session scan A c2be31609844

Subscribe to this mod's changes

networking-load-balancing-interviewer is a skill published in the GitHub repository PrepLabsAI/InterviewMentor (102 stars, last pushed 2mo ago), licensed MIT. It adds 72 tokens to every session and 2,445 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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