Rakuten coding interview
questions, leaked.
6 problems reported across recent Rakuten interviews. Top patterns: array, greedy, dynamic programming. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Rakuten's assessment leans heavily on arrays and greedy thinking. With 5 medium problems and just 1 easy, you're looking at a gauntlet where one mistake compounds fast. Array manipulation dominates the problem set, appearing in 4 of 6 questions. The good news: the patterns are tight and repeatable. The bad news: you'll need to nail them cleanly. If you blank mid-interview on a greedy choice or array rotation, StealthCoder runs invisibly and surfaces a working solution in seconds, keeping you moving while the proctor sees nothing.
Top problems at Rakuten
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Longest Happy String | MEDIUM | 100.0 | 65% | String · Greedy · Heap (Priority Queue) |
| 02 | Best Time to Buy and Sell Stock II | MEDIUM | 100.0 | 70% | Array · Dynamic Programming · Greedy |
| 03 | Best Time to Buy and Sell Stock | EASY | 100.0 | 55% | Array · Dynamic Programming |
| 04 | LRU Cache | MEDIUM | 100.0 | 45% | Hash Table · Linked List · Design |
| 05 | Rotate Image | MEDIUM | 100.0 | 78% | Array · Math · Matrix |
| 06 | 3Sum | MEDIUM | 100.0 | 37% | Array · Two Pointers · Sorting |
Frequencies derived from public community-tagged interview reports. Click a row to view on LeetCode.
You have a week, maybe less. You can't out-grind the list above. StealthCoder runs invisibly during the actual Rakuten OA. The proctor cannot see it. Screen share cannot detect it. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoder- array4 · 67%
- greedy2 · 33%
- dynamic programming2 · 33%
- string1 · 17%
- heap priority queue1 · 17%
- hash table1 · 17%
- linked list1 · 17%
- design1 · 17%
- doubly linked list1 · 17%
- math1 · 17%
Arrays are the spine of Rakuten's assessment. You'll see rotation, two-pointer traversal, and stock-trading greedy logic stacked back to back. Greedy and dynamic programming split a lot of overlap: both appear in Best Time to Buy and Sell Stock II, so understand when DP exhaustion beats a one-pass greedy scan. The harder gear shift comes from design questions like LRU Cache, which bury array skills inside data structure thinking. Hash table, linked list, and doubly-linked list all converge there. String and heap problems are lower frequency but punchy. Start by owning array manipulation and greedy patterns, then cement LRU Cache as your coda. When you hit the OA, you'll have seen the core shapes. StealthCoder is your hedge for the moment you don't.
Companies with similar patterns
If you prepped for Rakuten, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Rakuten.
Memorizing every problem above in a week is a fantasy. StealthCoder is the hedge: an AI overlay that's invisible during screen share. It reads the problem on screen and surfaces a working solution in under 2 seconds. 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.
Rakuten interview FAQ
Should I prioritize arrays first for Rakuten?+
Yes. Arrays appear in 4 of 6 problems, including Easy and all Medium tiers. Rotation, two pointers, and greedy indexing are the core shapes. Once arrays click, move to greedy and dynamic programming, which overlap heavily in stock-trading questions.
How much time should I spend on the LRU Cache problem?+
Significant. It's the only design problem in Rakuten's set and forces you to combine hash tables, doubly-linked lists, and caching logic. It's a common blocker. Master the doubly-linked list pointer manipulation first, then layer on the hash map.
Is greedy enough for stock-trading problems?+
Not always. Best Time to Buy and Sell Stock II rewards greedy thinking, but Best Time to Buy and Sell Stock (the single-transaction version) is purely DP. Understand both approaches. Greedy works when you can resell immediately; DP when you're locked to one buy-sell pair.
What if I see a string or heap problem on test day?+
Both are lower frequency in Rakuten's patterns but both appear at least once. Longest Happy String combines string, greedy, and heap logic. Drill heap ordering and greedy character selection once you've locked arrays and LRU Cache.
How many practice problems should I solve before the OA?+
You have 6 known problems. Solve each 2 to 3 times until the code flows without hesitation. Then drill 3 to 4 additional array and greedy problems to build pattern confidence. Rakuten's OA will test variations on shapes you've seen.