Complete Guide to Japan IT Job Interviews: Japanese Interview Preparation for Korean Engineers

Complete Guide to Japan IT Job Interviews

For Korean engineers who want to move to a Japanese IT company, the interview is one of the biggest hurdles. Many people miss opportunities not because of insufficient technical skills, but because of the unique environment of a Japanese-language interview. This guide walks you step by step through everything you need to completely prepare for a Japanese IT company interview from start to finish.

The Japanese IT job market is becoming increasingly open to foreign engineers. Especially since 2024, as the IT talent shortage has intensified, many companies are actively hiring foreign engineers. However, the hiring process itself still often follows Japan's own unique approach.

1. Understanding the Structure of Japanese IT Interviews

Typical Hiring Process

Japanese IT company hiring processes vary somewhat by company, but generally proceed through the following stages.

Document Screening

Japanese job applications often require two documents:

• 履歴書 (りれきしょ, Rirekisho): Basic resume. Records personal information, educational history, certifications, etc. Many companies in Japan still use a standardized format (JIS standard).
• 職務経歴書 (しょくむけいれきしょ, Shokumu Keirekisho): Work history document. This is the equivalent of a Korean portfolio or resume, but with a different format. This document is the most important in IT hiring.

First Interview: HR Interview

Also called 人事面接 (じんじめんせつ, Jinji Mensetsu). Conducted by HR staff or a hiring manager. Primarily assesses:

• Motivation for applying
• Career overview
• Understanding of the company
• Japanese communication ability
• Basic character/personality

At this stage, communication ability and cultural fit with the company are evaluated more than technical depth.

Second Interview: Technical Interview

Called 技術面接 (ぎじゅつめんせつ, Gijutsu Mensetsu) or テクニカル面接. Conducted by working engineers or a tech lead. Key content:

• Technical competency check
• In-depth questions about past projects
• Coding test (varies by company)
• System design questions
• Opinions on technology trends

Third or Final Interview

Called 役員面接 (やくいんめんせつ, Yakuin Mensetsu) or 最終面接 (さいしゅうめんせつ, Saishuu Mensetsu). Executive attendance, primarily verifying:

• Vision and growth potential
• Team culture fit
• Long-term career plan
• Confirming conditions (salary, start date, etc.)

Special Considerations for Foreign Applicants

When foreign engineers apply, there are additional matters that tend to be verified:

• 日本語能力 (にほんごのうりょく, Japanese ability): Many companies require JLPT N2 or above. At the N2 level, basic communication in the workplace is possible, but N1 is significantly more advantageous.
• ビザの状況 (びざのじょうきょう, Visa status): Visa status check. A work visa (技術・人文知識・国際業務, Gijutsu/Jinbun/Kokusai) is required.
• 在留資格 (ざいりゅうしかく, Residence status): Questions about residence status may arise.

2. How to Write the Shokumu Keirekisho

Key Differences from a Korean Resume

Korean resumes typically follow a company format or the format of platforms like Job Korea, but the Japanese Shokumu Keirekisho is a free format (自由形式) with industry conventions.

Key differences:

1. Length: Korean resumes prefer 1-2 pages, but a Japanese Shokumu Keirekisho allows 3-5 pages. The more experience you have, the more detail you should provide.

2. Expressing achievements: It is better to include more specific numbers and results than in Korean resumes. Instead of 「パフォーマンスを改善した」(improved performance), write specifically like 「クエリのパフォーマンスを50%改善し、ページロード時間を3秒から1.5秒に短縮した」(improved query performance by 50%, reducing page load time from 3 seconds to 1.5 seconds).

3. Expressing technology stack: Clearly express proficiency in each technology. For example:

   • 実務経験あり (have practical experience)
   • 3年以上の経験 (3+ years of experience)
   • チームリードとして使用 (used as a team lead)

Basic Structure of a Shokumu Keirekisho

職務経歴書

[Name]  作成日: [Date]

■ 職務要約
[3-5 line summary. Career highlights]

■ 職務経歴

[Company name] [Period of employment]
業種: [Industry]
事業内容: [Business description]
雇用形態: 正社員

担当業務:
・[Job responsibilities 1]
・[Job responsibilities 2]

実績:
・[Achievement 1: with specific numbers]
・[Achievement 2]

使用技術:
[List of technologies used]

■ 保有スキル

プログラミング言語: Python (5年), Go (3年), TypeScript (2年)
フレームワーク: FastAPI, Django, React
インフラ: AWS (EC2, RDS, Lambda, ECS), Terraform, Kubernetes
その他: Git, Docker, CI/CD (GitHub Actions, Jenkins)

■ 資格・語学
・JLPT N2 取得 ([year acquired])
・AWS Certified Solutions Architect

■ 自己PR
[Self-PR 3-5 lines]

Writing Your Shokumu Keirekisho with AI

Using AI, you can convert a resume written in Korean into a Shokumu Keirekisho suited for Japanese IT companies. Try this prompt:

"Here is my Korean resume. Please convert this into a
Shokumu Keirekisho format suitable for Japanese IT companies.
- Express achievements with specific numbers
- List technologies with years of experience
- Use natural Japanese business expressions
- Emphasize points that appeal to IT engineer hiring

[Korean resume content]"

Self-PR (自己PR) Writing Strategy

A good self-PR is not merely a list of your career history — it should appeal to why you are the right talent for this company.

Structure of a good self-PR:

1. Strengths + evidence (achievements/experience)
2. How you will contribute after joining
3. Career vision

Example:

「私の強みは、技術力とコミュニケーション能力のバランスです。
バックエンド開発5年間で、大規模サービスのパフォーマンス改善や
チームリードを経験しました。特にマイクロサービス移行プロジェクトでは、
チームの生産性を40%向上させることができました。

貴社のプロダクト開発において、私の経験を活かして
即戦力として貢献できると考えております。
また、継続的な学習を通じて、常に最新技術を取り入れる姿勢を
大切にしています。

日本語はN2レベルですが、技術的なコミュニケーションには
問題ないと考えており、日々向上に努めています。」

(My strength is the balance between technical skills and communication ability. In five years of backend development, I have experience in performance improvement for large-scale services and team leadership. In particular, in a microservice migration project, I was able to improve team productivity by 40%. I believe I can contribute as an immediate asset in your company's product development by leveraging my experience. I also value the attitude of always incorporating the latest technology through continuous learning. My Japanese is at the N2 level, but I believe there are no problems with technical communication, and I strive to improve every day.)

3. Self-Introduction (自己紹介) Templates

1-Minute Self-Introduction

Used when you receive a request like 「自己紹介をお願いします」(Please introduce yourself) at the start of an interview:

「はじめまして、[Name]と申します。

韓国出身で、現在日本語はN2レベルです。

バックエンドエンジニアとして[Years]年の経験があり、
主にPythonとAWSを使ったマイクロサービスの開発・運用を
担当してきました。

直近では[Recent project/achievement]に取り組み、[Achievement]を達成しました。

本日はよろしくお願いいたします。」

(Nice to meet you, my name is [Name]. I am from Korea, and my current Japanese level is N2. I have [Years] years of experience as a backend engineer, mainly responsible for developing and operating microservices using Python and AWS. Most recently, I worked on [Recent project/achievement] and achieved [Achievement]. Thank you for having me today.)

3-Minute Self-Introduction

When a more detailed self-introduction is required:

「はじめまして、[Name]と申します。韓国のソウル出身で、
現在[Location]に在住しております。

まず、経歴についてご説明させてください。
[University]のコンピュータサイエンス学科を卒業後、
[First company]でエンジニアとしてキャリアをスタートしました。
そこでは主に[Job responsibilities]を担当し、[Achievement]を達成しました。

その後[Second company]に転職し、より大規模なシステムの開発に
携わりました。特に[Notable experience]の経験は私のエンジニアとしての
成長に大きく貢献しました。

日本のIT業界に興味を持ったきっかけは[Reason for interest in Japanese IT]です。
技術的な観点からも、日本のエンジニアリング文化からも
多くを学べると感じています。

貴社に対しては、[Specific reason for interest in this company]という点から
大変興味を持っております。

本日は貴重なお時間をいただき、ありがとうございます。
よろしくお願いいたします。」

Personalizing Your Self-Introduction with AI

How to personalize your self-introduction with AI:

"Here is my basic information. Based on this, please write
a 1-minute self-introduction in Japanese to use in a Japanese IT company interview.

- Name: [Name]
- Experience: 5 years as a backend engineer
- Key technologies: Python, FastAPI, AWS
- Recent achievement: 40% latency reduction
- Japanese level: JLPT N2
- Why I applied to this company: [Reason]

Conditions:
- Natural business Japanese
- Not too stiff
- Length that can be delivered within 1 minute"

4. Technical Interview Q&A in Japanese

30 Frequently Asked Questions and Model Answer Patterns

Strengths/weaknesses related

「自分の強みと弱みを教えてください」 (Please tell me your strengths and weaknesses)

Model answer:

「強みは問題解決力です。技術的な課題に直面したとき、
単に既存の解決策を適用するのではなく、根本原因を分析して
最適なアプローチを考える習慣があります。

弱みは、細部にこだわりすぎることがある点です。
品質へのこだわりは重要ですが、リリーススケジュールとの
バランスを取ることを意識して改善しています。」

(My strength is problem-solving ability. When facing a technical challenge, I have a habit of analyzing the root cause and thinking about the optimal approach rather than simply applying an existing solution. My weakness is that I can sometimes get too caught up in details. While attention to quality is important, I am consciously working to improve the balance with release schedules.)

Technology trends related

「最近注目しているAI技術について教えてください」 (Please tell me about AI technologies you have been paying attention to recently)

Model answer:

「LLMを活用したアプリケーション開発に最も注目しています。
特にRAGアーキテクチャを使ったエンタープライズ向けの
知識管理システムには大きな可能性を感じています。

実際に個人プロジェクトでLangChainを使った
社内ドキュメント検索システムを作成し、
セマンティック検索の精度向上に取り組んでいます。

ただし、LLMのハルシネーション問題や
コスト最適化については課題があると考えており、
実用化にはまだ注意が必要だと思っています。」

(I am most interested in application development utilizing LLMs. In particular, I see great potential in knowledge management systems for enterprise use with RAG architecture. I have actually created an internal document search system using LangChain as a personal project, and I have been working to improve the accuracy of semantic search. However, I think there are challenges regarding LLM hallucination issues and cost optimization, and I believe caution is still needed for practical use.)

Teamwork related

「チームでの開発経験を教えてください」 (Please tell me about your team development experience)

Model answer:

「前職では8名のチームでスクラム開発を行っていました。
テックリードとして、コードレビューの文化醸成と
ドキュメント整備を主導しました。

最も印象的な経験は、サービスのマイクロサービス移行プロジェクトです。
異なる背景を持つメンバーが多く、技術的な合意形成に苦労しましたが、
ADR(Architecture Decision Record)を導入することで
意思決定の透明性を高めることができました。

この経験から、技術力だけでなく
コミュニケーションとドキュメンテーションの重要性を
強く認識しました。」

(At my previous company, I worked with a team of 8 people using Scrum. As a tech lead, I led efforts to cultivate a code review culture and improve documentation. The most impressive experience was a service microservice migration project. There were many members with different backgrounds, and it was difficult to reach technical consensus, but by introducing ADRs (Architecture Decision Records), I was able to increase the transparency of decision-making. From this experience, I strongly recognized the importance of communication and documentation, not just technical skills.)

Incident response experience

「障害対応の経験を教えてください」 (Please tell me about your incident response experience)

Model answer:

「本番環境でデータベースの接続プールが枯渇する障害を
経験したことがあります。

午前2時のアラートで気づき、即座にスロークエリログを確認。
N+1問題が原因であることを特定し、
まず接続プールの上限を一時的に引き上げて
サービスを安定化させました。

翌日にチームと原因分析を行い、
クエリの最適化とインデックスの追加で恒久対応。
同様の問題を早期発見するためのモニタリング強化も実施しました。

この経験から、事後レビュー（ポストモーテム）の
文化の重要性を学び、以降は再発防止策の文書化を
習慣化しています。」

(I experienced an incident where the database connection pool was exhausted in the production environment. I noticed from a 2 AM alert and immediately checked the slow query log. I identified the N+1 problem as the cause, and first temporarily raised the connection pool limit to stabilize the service. The next day I performed root cause analysis with the team and implemented a permanent fix by optimizing queries and adding indexes. I also strengthened monitoring to detect similar problems early. From this experience, I learned the importance of post-incident review (postmortem) culture, and since then I have made it a habit to document countermeasures to prevent recurrence.)

System design related

「スケーラブルなシステムの設計経験を教えてください」 (Please tell me about your experience designing scalable systems)

Model answer:

「ECサイトのバックエンドを、月次ユーザー10万人から
100万人にスケールするプロジェクトを担当しました。

まずボトルネック分析を行い、
データベースへの集中アクセスが主な課題であることを特定。
読み取り系をリードレプリカに分散し、
頻繁にアクセスされるデータをRedisでキャッシュしました。

また、画像処理などの重い処理はメッセージキュー経由で
非同期化し、API のレスポンスタイムを改善しました。

結果として、ピーク時のレスポンスタイムを
平均2秒から0.3秒に改善できました。」

(I was in charge of a project to scale an e-commerce site backend from 100,000 monthly users to 1,000,000. I first performed bottleneck analysis and identified concentrated access to the database as the main issue. I distributed read operations to read replicas and cached frequently accessed data with Redis. I also made heavy processes like image processing asynchronous via a message queue, improving API response times. As a result, I was able to improve peak response time from an average of 2 seconds to 0.3 seconds.)

Coding Test Preparation

Many Japanese IT companies require a coding test before or after the interview. Commonly used platforms:

• LeetCode
• AtCoder (especially popular in Japan)
• HackerRank
• CodeIQ (focused on Japanese companies)

When problems are presented in Japanese, knowing the following vocabulary will help:

• 整数 (せいすう): integer
• 配列 (はいれつ): array
• 文字列 (もじれつ): string
• 繰り返し (くりかえし): loop/repetition
• 条件 (じょうけん): condition
• 関数 (かんすう): function
• 戻り値 (もどりち): return value
• 計算量 (けいさんりょう): computational complexity
• 最大値 (さいだいち): maximum value
• 最小値 (さいしょうち): minimum value

5. Interview Practice with AI

Running a Mock Interview with Claude

Using AI as an interviewer for mock interview practice is extremely effective for real-world preparation.

Run a mock interview with Claude using this prompt:

"You are a technical interviewer at a Japanese IT company.
I am a Korean backend engineer who has used Python and AWS for 5 years.
My Japanese is at the N2 level.

Please conduct a mock interview with the following rules:
1. Ask all questions in Japanese
2. Also evaluate the naturalness of my Japanese in my answers
3. Provide feedback in English after each answer
4. If there are better expressions, give examples

Please start by asking for my self-introduction."

Improving Answers with ChatGPT

How to ask AI to review a draft interview answer:

"Below is a Japanese answer I've prepared for the question
'What are your strengths?' in a Japanese IT company interview.
Please improve it from the following perspectives:

1. Natural Japanese business expression
2. More persuasive structure
3. Points that appeal in IT interviews
4. Grammar error correction

[My draft answer]"

Analyzing Interview Feedback

How to ask AI for feedback after an interview:

"I just had an interview at a Japanese IT company. Please analyze
the following question and my answer and give me improvements for the next interview:

Question: [Question content]
My answer: [Answer content]
Interviewer's reaction: [Any notable reactions]

Analysis requested:
1. Strengths of the answer
2. Points to improve
3. A better model answer example
4. Appeal points I missed"

6. Interview Characteristics by Japanese IT Company Type

Large SI (SIer) Companies

Japanese SIers include large companies like NTT Data, Fujitsu, and NEC. Characteristics:

Interview style: More formal atmosphere. Accurate use of keigo (honorific language) is important.

Main question tendencies:

• Project management experience
• Client communication experience
• Teamwork and collaboration approach

Preparation tips:

• Use 丁寧語 (ていねいご, polite language) and 尊敬語 (そんけいご, respectful language) distinctly
• Practice formal expressions like 「〜でございます」「いたします」
• Actively emphasize your intention for long-term employment

Foreign-Affiliated IT Companies

Characteristics of foreign-affiliated companies like Google Japan, Amazon Japan, and Microsoft Japan:

Interview style: Relatively relaxed atmosphere. Using both English and Japanese may sometimes be acceptable.

Main question tendencies:

• Behavioral interviews using the STAR method
• System design interviews
• Coding interviews (LeetCode style)

Preparation tips:

• Prepare in both English and Japanese
• Answer with focus on specific numbers and achievements
• Familiarize yourself with company-specific values like Leadership Principles

Startups

Characteristics of IT startups like Mercari, SmartHR, and Sansan:

Interview style: Casual atmosphere. Many opportunities for reverse interviews (asking your own questions).

Main question tendencies:

• Adaptability in a rapidly changing environment
• Self-directed learning ability
• Cultural fit with the company

Preparation tips:

• Deeply understand the company's mission and products
• Prepare specifically what you want to do after joining
• Prepare 5-10 reverse interview questions

Conclusion: Interview Preparation Checklist

Things to check before the interview day:

One week before

• Final review of Shokumu Keirekisho
• Practice self-introduction 5+ times (record and self-evaluate)
• Research the company (products, tech stack, news)
• 2+ mock interviews with AI

The day before

• Confirm interview location/method (in-person/online)
• Final review of expected questions
• Early bedtime

The day of

• Leave with plenty of time (arrive 15 minutes early)
• Start with 「よろしくお願いいたします」
• Be honest about things you don't know
• Always prepare reverse questions

Getting a job at a Japanese IT company is challenging but a fully achievable goal. With thorough preparation and smart use of AI tools, you can make your dream come true!