Doubly-Linked List interview questions
9 doubly-linked list problems tagged across recent interview reports. Drilled most heavily by linkedin, snap, and oracle.
Doubly-Linked List problems are about building and manipulating structures where each node points forward and backward, enabling bidirectional traversal and efficient insertion or deletion at any position. With 9 core problems and heavy adoption at LinkedIn, Snap, and Oracle, this pattern often appears in live OAs as a design challenge, LRU caches, text editors, browser history stacks. If you hit a hard doubly-linked list variant during your assessment, StealthCoder reads the problem and solves it invisibly, keeping your momentum alive.
Most-asked doubly-linked list problems
| # | Problem | Diff | # Companies | Pass % |
|---|---|---|---|---|
| 01 | LRU Cache | MEDIUM | 109 | 45% |
| 02 | LFU Cache | HARD | 17 | 47% |
| 03 | Design a Text Editor | HARD | 8 | 47% |
| 04 | Design Authentication Manager | MEDIUM | 6 | 58% |
| 05 | All O`one Data Structure | HARD | 5 | 44% |
| 06 | Design Browser History | MEDIUM | 5 | 78% |
| 07 | Max Stack | HARD | 4 | 46% |
| 08 | Flatten a Multilevel Doubly Linked List | MEDIUM | 3 | 61% |
| 09 | Convert Binary Search Tree to Sorted Doubly Linked List | MEDIUM | 2 | 65% |
You can't drill every doubly-linked list variant before the assessment. StealthCoder runs invisibly during screen share and solves whichever variant they throw at you. No browser extension. No detection signature. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoderDoubly-linked list problems split into two camps: explicit list manipulation (flatten multi-level structures, convert trees to sorted lists) and data structure design (LRU/LFU caches, authentication managers, design-a-text-editor). The pattern is almost always about maintaining bidirectional pointers correctly and recognizing when forward-and-backward traversal cuts algorithmic complexity. You'll know you're in a doubly-linked list problem when the prompt hints at efficient removal or reordering, or when it names a cache or undo/redo system. Drill pure manipulation problems first (flatten, convert), then move to cache designs (LRU, LFU). When a complex design variant lands in your live OA and you're unsure of the pointer logic, StealthCoder solves it in seconds while the proctor sees nothing.
Companies that hire most on doubly-linked list
9 doubly-linked list problems.
You won't drill them all. Pass anyway.
Doubly-Linked List is one of the patterns interviews actually filter on. Memorizing every variant in a week is a fantasy. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds, no matter which doubly-linked list flavor lands in your live OA. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Doubly-Linked List interview FAQ
How many doubly-linked list problems should I drill before my OA?+
All 9 core problems is the baseline. LinkedIn and Snap ask them heavily, 14 and 11 problems respectively across their hiring funnel. If your target company is in the top 10, expect 1-2 designs. Drill LRU and LFU caches first; they're the most common live variants.
Is doubly-linked list the most important pattern for system design rounds?+
It's not the most important overall, but it's critical for cache and undo-redo designs. You'll see it in medium and hard design problems at companies like Salesforce and DoorDash. It's often nested inside a larger design, not standalone.
How do I recognize a doubly-linked list problem in the wild?+
Look for: explicit mention of bidirectional traversal, cache eviction policies (LRU/LFU), undo/redo mechanics, or design prompts naming 'most recently used' or 'least frequently used'. If the problem asks you to remove or reorder nodes efficiently, it's likely doubly-linked.
Which company drills doubly-linked list the hardest?+
LinkedIn leads with 14 problems tagged to this pattern across their hiring pipeline. Snap and Oracle follow at 11 and 10 respectively. If you're interviewing there, cache and text editor designs are almost guaranteed.
What's the hardest doubly-linked list problem to code live?+
Design-a-text-editor and LFU-cache are the trickiest, they demand both correct pointer management and efficient data structure composition. If you freeze on pointer edge cases or cache eviction logic during your live OA, that's where StealthCoder is your safety net.