【SaaS】Sales Platform_Senior Backend Engineer

About Geniee Inc.

We were founded in April 2010 with the goal of creating a global tech company from Japan, like GAFA. We went public only seven years after our founding and have kept increasing both revenue and profit since then. We are a fast-growing company. As a marketing technology company, we operate an ad platform business, a marketing SaaS business, and a digital PR business. We are a rare company that has both ad technology and marketing technology products, and we continue to grow. In 2020, we were selected in the Financial Times “High-Growth Companies Asia-Pacific” ranking. In 2023, we established JAPAN AI Inc. as a wholly owned subsidiary to focus on the cutting-edge AI business. JAPAN AI’s technology creates synergy with Geniee’s existing products, and the group is achieving high growth. By offering state-of-the-art solutions, we help customers improve efficiency and productivity. Note: The “High-Growth Companies Asia-Pacific 2020” ranking surveyed more than 50 million companies in 12 countries in the Asia-Pacific region. It selected 500 companies based on revenue growth from 2015 to 2018. Geniee ranked 357th overall and 11th among technology companies from Japan. https://geniee.co.jp/news/20200525/232(https://geniee.co.jp/news/20200525/232)

Why We’re Hiring

“Use your experience to lead our team to the next stage.” Our in-house AI-powered SFA/CRM, GENIEE SFA/CRM, has gained many customers. It is growing 300% YoY and is entering a new phase as we expand into the enterprise market. However, our development organization is feeling strong growing pains. Rapid expansion has left our structure unfinished, support for high-potential young members is behind, and we carry technical debt. To maximize product value and secure our competitiveness, we must solve these issues and mature both our organization and technology. This role is not just to fill a seat. With your rich SaaS development experience and leadership, we want you to tackle our “technical debt” as room for growth and act as a trusted senior who guides our highly capable junior engineers—the technical pillar of the team. Join us to build a development organization with world-class technical strength and take our product to the next level. Note: GENIEE SFA/CRM won 1st place in the SFA (sales support system) category at the BOXIL SaaS AWARD 2025. Press release: BOXIL SaaS AWARD 2025.(https://geniee.co.jp/news/20250304/771)

Job Description

As a backend engineer who will technically lead our fast-growing SFA/CRM product, you will take on a wide range of responsibilities—from design and development to supporting team growth.• Design, build, and maintain robust, high-performance software applications and systems. Tackle complex technical challenges with creative and effective solutions. Produce clean, efficient, and well-documented code that adheres to best practices. Lead discussions on technical design, architecture, and long-term system strategy. Mentor junior engineers, providing guidance and sharing technical expertise. Conduct thorough code reviews to ensure quality, consistency, and maintainability. Keep current with emerging technologies, frameworks, and industry trends. Actively contribute to Agile processes such as sprint planning, daily stand-ups, and retrospectives. Collaborate closely with product managers, designers, business owners,and fellow engineers to deliver aligned outcomes. Help define technical specifications, project scopes, and implementation plans.

Position

In this position, you are expected to be the technical compass of the team, not just a developer.People management—such as goal setting and evaluations—will be handled by an experienced engineering manager. This environment allows you to focus 100% on technical leadership, technical decision-making, and team growth. You will leverage your experience to lead technology selection and architecture design, while mentoring junior members to raise the team’s overall technical level. Your impact will directly shape product quality and the culture of our engineering organization—this is a highly important role.

Why You’ll Love This Role

Your experience will define our “standards” Because the organization is still maturing, your experience will become the foundation of our processes and culture. You’ll take ownership of building core pillars—architecture design, coding conventions, and training systems—gaining rare, high-impact experience. Grow high-potential juniors into world-class engineers We have highly motivated members in their 20s–30s, but structured growth support hasn’t fully caught up. You’ll mentor them closely and scale together as a team—an experience that brings strong purpose and joy. Tackle advanced challenges in enterprise SaaS As we expand into the enterprise market, we face demanding problems in scalability, performance, and security. You’ll lead the resolution of complex issues, including paying down technical debt, and further increase your market value as an engineer. Build at the forefront of AI-powered product development We embed our in-house AI technology into the product to create the next generation of SFA/CRM. You’ll deepen your knowledge of AI-driven features and gain practical, hands-on skills in an environment built for innovation.

Work Style

Primarily office-based, with the option to work from home two days per week.Note: This may change in the future depending on circumstances.

Tech Stack

Backend: Python, FastAPI Frontend: React, Next.js, TypeScript Mobile: iOS: Swift / Android: Kotlin Cloud Infrastructure: Amazon ECS Container: Docker, AWS Lambda Test Tools: Playwright, Jest, Storybook, Chromatic DB: MySQL, BigQuery, MongoDB, AWS OpenSearch, AWS Redis CI/CD: GitHub Actions, CodeBuild Design Philosophy: DDD, Clean Architecture Version Control System: GitHub Other Tools: Slack, Jira, Confluence, Google Workspace AI Coding: Company covers the cost of using AI tools such as JAPAN AI SaaS services, Curosor, CharGPT, Claude, CodeRabbit, etc. Others: Windows/Mac available by choice

Required Qualifications

3+ years of experience developing web applications using modern frameworks. 3+ years of backend development experience with Python and other programming languages. Proven experience in developing SaaS products for enterprise customers. More than 2 years of experience mentoring or leading team members in a senior or leadership capacity. Knowledge with major cloud platforms such as AWS and GCP. Practical experience with database technologies, including both SQL and NoSQL systems.

Preferred Qualifications

Experience leading or managing a development team. Hands-on experience implementing and utilizing automated testing frameworks. Japanese language proficiency: JLPT N2 or conversational level. Proficiency in Vietnamese is a strong plus (to facilitate collaboration with our Vietnam-based development team).

We’re Looking For

Someone passionate about analyzing complex technical challenges and driving solutions Someone who takes joy in the team’s growth and success, and actively shares their own experience Someone who enjoys unstructured environments and takes ownership to build processes and culture Someone who collaborates across departments to tackle shared problems together

Selection Process

CV Screening → Coding test → Multiple Interviews → Final Interview(Reference checks and SPI test are required before the final interview.)

SaaS

Sales Platform_Senior Backend Engineer

雇用形態

正社員

給与

年収 8,000,000円 〜 15,000,000円OT beyond 45h paid separately Reviews: 2x/year (Apr, Oct), Bonuses: 2x/year (May, Nov) SO available

勤務地

163-6006 Sumitomo Fudosan Shinjuku Oak Tower, 5th/6th Floor, Nishi-Shinjuku, Shinjuku-ku, Tokyo

Learning and Development Support

・AI Tool Usage Support: Company covers the cost of using AI tools such as JAPAN AI SaaS services, Curosor, CharGPT, Claude, etc. ・Development Tool Support: If a desired development tool is paid, the cost is covered (up to 30,000 yen per year) ・Book Purchase Assistance: Company covers the cost of purchasing books for learning, such as technical books (up to 30,000 yen per half-year) ・Language Learning / Qualification Support: Company covers the cost of Japanese or English learning programs and qualification acquisition ・Refresh Allowance: Company covers the cost of services used for personal refreshment (up to 5,000 yen per month) e.g., gym, yoga, chiropractic, aquarium, movies, theme park tickets, etc. ・Housing Allowance: Housing allowance provided for those living in designated areas (up to 30,000 yen per month)会社情報

会社名

株式会社ジーニー

事業内容

・広告プラットフォーム事業 ・マーケティングSaaS事業 ・デジタルPR事業

設立年月日

2010年4月14日

代表者

代表取締役社長 工藤 智昭

資本金

100百万円（連結、2025年3月末現在）

従業員数

877名（連結、2025年3月末現在）

本社所在地

東京都新宿区西新宿6-8-1 住友不動産新宿オークタワー5/6階

就業時間

10:00～19:00 ※土日祝は休業日となります ※出向の場合は、出向先の規程に準じます

待遇・福利厚生

<正社員> ・書籍購入補助（半期 30,000円まで） ・リフレッシュ手当（毎月 5,000円まで） ・部活動手当（毎月5,000円まで） ・家賃手当（当社指定の駅を対象とし毎月30,000円まで） ・シャッフルランチ/ディナー（四半期に一度ランチ1,000円まで、ディナー5,000円まで） ・資格取得支援制度、英語学習支援制度（業務に必要な場合のみ） ・リフレッシュ休暇制度（3年間継続勤務した社員へ毎年付与される特別休暇 2日） ・定期健康診断（年1回） ・従業員持株会 <契約社員> ・書籍購入補助（半期 30,000円まで） ・リフレッシュ手当（毎月 5,000円まで） ・部活動手当（毎月5,000円まで） ・シャッフルランチ/ディナー（四半期に一度ランチ1,000円まで、ディナー5,000円まで） ・リフレッシュ休暇制度（3年間継続勤務した社員へ毎年付与される特別休暇 2日） ・定期健康診断（年1回）

保険

・社会保険完備

諸手当

・交通費全額支給

代表プロフィール

早稲田大学大学院卒業後、株式会社リクルート（現 株式会社リクルートホールディングス）へ入社。2010年4月株式会社ジーニーを創業、代表取締役社長に就任。2023年4月には戦略的AIカンパニーJAPAN AI株式会社を設立し、同社の代表取締役社長を兼任している。

企業成長ランキング

■ Financial Times社発表のアジア成長企業ランキング2020を受賞 Financial Times社とStatista社が、アジア太平洋地域12カ国5,000万以上の企業を対象に実施した調査で、飛躍的活躍を遂げた企業500社に選出されました。

休日休暇

完全週休二日制 所定休日：土・日・祝日 休暇：年次有給休暇、夏季休暇（3日）、年末年始休暇（12月31日〜1月3日）、慶弔休暇

グループ会社

CATS株式会社（日本） JAPAN AI株式会社（日本） ソーシャルワイヤー株式会社（日本） Geniee International Pte., Ltd.（シンガポール） Geniee Vietnam Co., Ltd.（ベトナム） PT. Geniee Technology Indonesia（インドネシア） PT. Adstars Media Pariwara（インドネシア） Zelto,Inc.（米国） AdPushup Software India Pvt Ltd.（インド）

備考

・試用期間 正社員/契約社員：1か月 ・受動喫煙対策 敷地内禁煙（屋外に喫煙場所設置） ・従事すべき業務の変更の範囲 会社の定める業務 ・就業の場所の変更の範囲 会社の定める場所 ・有期労働契約を更新する場合の基準に関する事項（通算契約期間又は更新回数の上限を含む） 更新の上限なし

福利厚生

<正社員> ・書籍購入補助（半期 30,000円まで） ・リフレッシュ手当（毎月 5,000円まで） ・部活動手当（毎月5,000円まで） ・家賃手当（当社指定の駅を対象とし毎月30,000円まで） ・シャッフルランチ/ディナー（四半期に一度ランチ1,000円まで、ディナー5,000円まで） ・資格取得支援制度、英語学習支援制度（業務に必要な場合のみ） ・リフレッシュ休暇制度（3年間継続勤務した社員へ毎年付与される特別休暇 2日） ・定期健康診断（年1回） ・従業員持株会 <契約社員> ・書籍購入補助（半期 30,000円まで） ・リフレッシュ手当（毎月 5,000円まで） ・部活動手当（毎月5,000円まで） ・シャッフルランチ/ディナー（四半期に一度ランチ1,000円まで、ディナー5,000円まで） ・リフレッシュ休暇制度（3年間継続勤務した社員へ毎年付与される特別休暇 2日） ・定期健康診断（年1回）

事業内容

・広告プラットフォーム事業 ・マーケティングSaaS事業 ・デジタルPR事業

必須スキル

• 3+ years of experience developing web applications using modern frameworks. 3+ years of backend development experience with Python and other programming languages. Proven experience in developing SaaS products for enterprise customers. More than 2 years of experience mentoring or leading team members in a senior or leadership capacity. Knowledge with major cloud platforms such as AWS and GCP. Practical experience with database technologies, including both SQL and NoSQL systems.

歓迎スキル

• Experience leading or managing a development team. Hands-on experience implementing and utilizing automated testing frameworks. Japanese language proficiency: JLPT N2 or conversational level. Proficiency in Vietnamese is a strong plus (to facilitate collaboration with our Vietnam-based development team).