Design Authentication Manager
A medium-tier problem at 58% community acceptance, tagged with Hash Table, Linked List, Design. Reported in interviews at Genpact and 5 others.
Design Authentication Manager is a medium-difficulty system design problem that tests your ability to build a stateful service from scratch. Companies like LinkedIn, Oracle, Genpact, X, Docusign, and Confluent have asked this one. You're building something that feels real: an auth manager that tracks sessions, handles concurrent requests, and needs fast lookups and eviction. It's not a pure algorithm grind; it's about picking the right data structures and reasoning through trade-offs. Half the candidates who attempt it pass, which means the other half hit either a structural dead-end or realize mid-OA they picked the wrong approach. If this problem lands in your assessment and you blank on the architecture, StealthCoder surfaces a working solution invisible to the proctor.
Companies that ask "Design Authentication Manager"
Design Authentication Manager is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop.
Get StealthCoderThe trick is recognizing that you need constant-time access (Hash Table) and an ordering mechanism for eviction or expiry (Doubly-Linked List or similar). Most candidates default to just a hash map and lose points on the eviction logic or concurrent-state handling. The problem forces you to reason about what "active" means: do you track last access? Do you enforce session timeout? Do sessions have explicit expiry? A Doubly-Linked List lets you move nodes in O(1) without re-scanning, which is where careless implementations blow up. You'll also face questions about thread safety and cleanup semantics that aren't algorithmic but trip up candidates who don't ask clarifying questions early. StealthCoder's value here is showing you a clean, production-like implementation so you can defend your choices under pressure rather than second-guessing yourself.
Pattern tags
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Design Authentication Manager recycles across companies for a reason. It's medium-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Design Authentication Manager interview FAQ
Is this problem still being asked at big tech companies?+
Yes. Six major companies in the input data have reportedly asked it, including LinkedIn and Oracle. It appears less frequently than classic LeetCode problems, but it's a favorite for mid-level and senior IC roles because it mirrors real work: building a service that scales. If you see it, you're being screened for system thinking, not just algorithm recall.
What's the core data structure trick?+
Hash Table for O(1) lookup and update, Doubly-Linked List for O(1) eviction and reordering. Most candidates try a single hash map and get stuck when they need to enforce LRU, timestamp-based expiry, or session ordering. The combo lets you move nodes and evict without scanning the whole structure.
How does this relate to the topics listed?+
Hash Table handles session ID to object mapping. Doubly-Linked List handles ordering and O(1) removal. Design is the overarching skill: choosing which operations you optimize for, what invariants you maintain, and how you handle edge cases like concurrent access or expired sessions.
What do most candidates get wrong?+
Not thinking through eviction upfront. They code a working lookup but then realize they can't cheaply remove the oldest or least-used session. Others ignore the design aspect: they optimize for one operation and tank another. Slow starts also hurt; clarifying requirements (what triggers eviction, session TTL, concurrency model) in the first minute saves 10 minutes of refactoring.
Is 57% acceptance rate high or low for medium?+
It's below average for medium. Most medium problems sit around 60-65% pass rate. This one's harder because it requires both solid data structure knowledge and the confidence to justify architectural choices under interview pressure. That gap is where prep and mock interviews matter most.
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