10 Mercari Software Engineer (New Grad, Tokyo) Interview Questions (2026)

Mercari's new-grad SWE loop in Tokyo in 2026 is a recruiter screen, a coding assessment, a technical phone interview, and a three to four round virtual onsite. Mercari is Japan's leading C2C marketplace with strong US presence and is known for being one of the most foreigner-friendly tech employers in Japan — English is the working language in many teams.

By Alex Chen, Founder, InterviewChamp.AI · Last verified 2026-05-19

Loop overview

Tokyo new-grad timelines run 6-9 weeks in 2026. Flow: recruiter screen → coding OA (60-90 min) → 45-min technical phone screen → three to four virtual onsite rounds. Onsite is two coding rounds, one design conversation, and one behavioral. Mercari supports visa sponsorship and has strong onboarding for international hires.

Behavioral (3)

Tell me about a time you adapted to a new culture or environment.

Frequently asked

Outline

Mercari is one of the most international workplaces in Japan. Show curiosity and adaptability. Pick a real example: studying abroad, joining a diverse team, learning a new domain. Avoid framing one culture as 'better'; show respectful curiosity.

Why Mercari? What about C2C marketplaces or our products interests you?

Frequently asked

Outline

Mercari pioneered mobile-first C2C marketplaces in Japan. Tie one product (Mercari Japan, Mercari US, Mercari Hallo) to personal interest. Mention awareness of the US expansion and the listing-fee model.

Tell me about a project you owned end-to-end.

Frequently asked

Outline

Mercari values ownership. Walk through: scope, your specific contribution, technical decisions, outcome. Quantify impact. Show what you would do differently in retrospect. Generic 'we built X' answers underperform.

Coding (LeetCode patterns) (4)

Given a list of items with prices and categories, return the average price per category.

Frequently asked

Outline

Single pass: hash map of category to (sum, count). Final pass: divide sum by count. O(n) time, O(categories) space. Walk through edge cases: empty category, single item, integer-overflow on sum.

Given two strings, find the minimum number of swaps to make them anagrams.

Frequently asked

Outline

Count character differences. The min swaps = number of mismatches / 2. Walk through: characters in A not in B contribute to one mismatch each. Discuss edge cases: same string (0 swaps), no overlap (impossible to make anagram).

Implement a function that returns the longest substring without repeating characters.

Frequently asked

Outline

Sliding window with hash map of last-seen indices. O(n) time, O(min(n,k)) space. Walk through a small example. Edge cases: empty string, all-unique, all-same.

Given a list of orders, group them by buyer and return each buyer's most recent order.

Occasionally asked

Outline

Hash map of buyer ID to most-recent order. Single pass, update if newer. O(n) time, O(buyers) space. Walk through edge case: buyer with single order.

Technical (2)

Implement a function that returns the top N most popular items in a marketplace given a stream of view events.

Frequently asked

Outline

Min-heap of size N keyed by view count. On each event: increment count, re-rank if needed. Discuss: time-decay (recent views weighted higher), distributed setting (per-shard then merge). O(log N) per event. Walk through one scenario.

How would you investigate a complaint that a seller's listing is not appearing in search?

Occasionally asked

Outline

Check the listing's index status. Verify content moderation flags (banned keywords, image issues). Check the seller's account state. Re-index if needed. Communicate clearly with the seller. Walk through structured investigation.

System / object-oriented design (1)

Design a search system for a marketplace with 100M+ listings.

Frequently asked

Outline

Discuss: search engine (inverted index, BM25), ranking (relevance + recency + seller reputation), faceted filters, autocomplete, real-time updates as new listings arrive. Walk through one search query. New-grads pass with framing, not search-engine internals.

Mercari interview tips

English is the working language in many teams. Japanese is a plus but not required.
Mercari has strong onboarding for international hires (visa support, relocation, language classes).
Go and Python dominate backend. TypeScript for web. Swift/Kotlin for mobile. The interview accepts any language.
Tokyo office is hybrid (2-3 days in-office). Confirm options with your recruiter.
Mercari values 'Go Bold' as a culture pillar. Bring stories of ambitious bets you took.

Frequently asked questions

How long is Mercari's SWE new-grad interview process in Tokyo in 2026?

Most reports show 6-9 weeks from OA to offer.

Does Mercari Tokyo sponsor work visas?

Yes — Mercari is one of the most foreigner-friendly tech employers in Japan, with strong visa support.

Do I need to speak Japanese to work at Mercari?

Not for many engineering teams — English is sufficient. Japanese is a plus and helps long-term.

What languages does Mercari use?

Go and Python dominate backend. TypeScript for web. Swift/Kotlin for mobile. The interview accepts any language.

Is Mercari Tokyo remote-friendly?

Hybrid is the norm (2-3 days in-office). Some teams support fully-remote within Japan. Confirm with your recruiter.

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