BrowseBrowse PathsPaths AI TreeAI MockMock SolveSolve PlaylistsPlaylists ListenListen

QnABox

Every IT interview answer — your way

support@qnabox.com

Interview prep for every IT job seeker

Learn

Career paths
AI learning tree
Browse questions
Mock interview
Playlists

Practice

Solve mode
Listen mode

Account

Log in
Sign up

Legal

Privacy
Terms
Contact

© 2026 QnABox. All rights reserved.

Built for job seekers · EN · हिन्दी · मराठी

Browse/System Design/Classic HLD Problems

Read Solve Listen

SeniorSenior (6–10 yrs)RedisSystem DesignAmazonMicrosoftPayPal

Design a rate-limited login API

Design login with brute-force protection across multiple app servers.

Answers use simple, clear English.

Your answer

Confidence

#security#rate-limit

News feed / Instagram feed Defense in Depth for Public APIs