Overview

Guided by Money Forward AI Vision 2026(https://www.linkedin.com/pulse/full-transcript-money-forward-announced-ai-strategy-vision-phwoc/?trackingId=sl33ZIGRFzkBJJv7wI9qsg%3D%3D), Money Forward is driving company-wide AX (AI Transformation) to deliver "digital workers" — AI agents that carry out business operations autonomously. The CDAO Office leads the AI and data strategy that makes this possible across the entire group.

This is a dedicated backend engineering role owning the application layer of a credit microservice (a private REST API) used across our Digital Bank and group-company fintech products. The microservice combines aggregated data produced by Databricks, machine learning model endpoints on SageMaker, and credit calculation logic inside the service itself to deliver credit information to the product side. In short, you will turn probabilistic, uncertain model output into deterministic API behavior a financial product can safely depend on .

Our small scrum team is currently focused on developing the credit evaluation model itself. For the FY2027 Digital Bank launch , however, we now need an API designed and built to serve that model's inference results with the traffic capacity and availability the product demands. Infrastructure, security, observability, and CI/CD are owned by our site reliability / infrastructure engineer, and model development by our machine learning engineers, so you can concentrate on the application itself - but because all three roles collaborate closely, we place real weight on understanding and being able to discuss areas outside your own remit.

Success is clearly defined: ensuring the FY2027 Digital Bank launch succeeds, from the standpoint of the credit microservice. Your mission is the architecture, implementation, and quality assurance that work backward from it.

Mission Priorities

Design, build, and assure the quality of a credit microservice (private REST API) capable of supporting the FY2027 Digital Bank launch
Stabilize machine learning model integration, and secure resilience through latency budgeting and fallback design
Establish development standards, architecture, and test strategy, and drive the team's technical decision-making

Responsibilities and Duties

As the primary application owner for the microservice, you will take the initiative within our scrum team and:

Design and implement the microservice architecture: a high-performance, low-latency service in Python and FastAPI, built for transaction volumes at the scale of tens of millions of users, including service boundaries and data ownership.
Design API contracts and reach agreement with stakeholders: OpenAPI schemas and error taxonomies, versioning and backward compatibility, and the process for changing contracts with Digital Bank and group-company stakeholders.
Bring models and credit logic into production, with resilience by design: the client-side interface for SageMaker endpoints, latency budget allocation, and timeout, retry, circuit breaker, and fallback behavior.
Implement credit domain logic with correctness and explainability: credit limit calculation with exhaustive boundary and failure cases, idempotency, reproducibility (linking input data, model version, and logic), and audit trail design.
Design for performance around data supply: how aggregated data in object storage is loaded, freshness management and consistent cutover, caching strategy, and asynchronous/parallel model calls.
Own quality, test strategy, and instrumentation: unit, contract, and load testing, regression processes for model swaps, structured logging and traceability, and SLI-driven instrumentation.
Lead technically and set standards: architecture selection, code review, and improvement and standardization of our development process.

Required Skills and Experience

5+ years of professional software engineering experience designing, building, and operating web APIs and microservices in Python or comparable languages
Track record with high-traffic, low-latency applications through efficient API design and application-level performance tuning
Contract and failure design experience for external system integrations including API schema, error taxonomy, timeouts, retries, and fallbacks
Strong test design and quality assurance background with experience embedding automated testing into the development process
Cloud application development experience on AWS using containerized environments and CI/CD pipelines
Ability to collaborate and build agreement across roles to drive technical specifications with SRE, machine learning engineers, and external stakeholders

Preferred Skills and Experience

Knowledge of machine learning integration and MLOps, including calling models on platforms like Amazon SageMaker and designing for inference latency
Understanding of data platforms and pipelines like S3, Glue, and Databricks to inform technical specs and incident analysis
Fluency reading and writing IaC with Terraform to propose infrastructure changes via pull requests
Experience in financial services, credit, or payments domains with exposure to auditability, traceability, and advanced security like mTLS, OAuth, or JWT
Leadership experience as a tech lead or scrum master with authority over architecture, code quality, and process standardization

Language Requirements

Business level Japanese (equivalent to JLPT N2 or above)
Basic business level English (equivalent to TOEIC 700 or above)
- If you do not have a qualification equivalent to TOEIC 700 or above, you will be required to take a company-designated test during the selection process.

※Please note that the interviews in the selection process will be conducted in Japanese.

Who We’re Looking For

Wants final accountability for product behavior with first-line responsibility for the correctness, speed, and availability of a credit API designed through to the last failure case
Drawn to converting the uncertainty of machine learning into the certainty of an API by designing an interface that behaves deterministically despite inference variance, latency, and model updates
Capable of standing at the boundary between roles to design the collaboration itself through clear ownership while picking up problems that fall between roles
Thrives on shaping systems during phases of genuine uncertainty and enjoys making the decisions that move projects forward when specifications and architecture are undecided
Eager to build infrastructure-scale products for the AI era by leading the launch phase of Digital Bank combined with shared credit evaluation using AI development tools such as Claude Code

Technology Stack

Backend / API: Python (FastAPI), Amazon API Gateway
Infrastructure / Cloud: AWS (ECS Fargate, S3, CloudWatch)
ML Serving: Amazon SageMaker (Model Endpoint)
DevOps / CI/CD: GitHub Actions, Docker, Terraform
Data Platform (integration target): Databricks, AWS Glue, S3
AI Development Tools: Claude Code and similar
Communication / Project: Slack, Notion

Work Environment

At Money Forward, we provide an environment where we can create world-class services together, and we are looking forward to welcoming you.

Provided PC Specs: We provide PCs equipped with the latest CPUs (MacOS or Windows). Custom-made PCs tailored to business requirements and replacements with the latest OS are also possible.
Systems to Enhance the Development Environment: Peripheral devices necessary for work (such as displays, mice, keyboards) can be purchased as office supplies. Generally, you can choose from standard products (catalog), and if conditions are met, you can apply for non-standard products as well.
Money Forward Library: We have a library system where you can freely borrow books, ranging from technical books to management books. Desired books can be purchased at the company's expense.
Referral Driven: We cover the cost of recruitment meals. There is a referral reward system.
Conference Participation Support: The company partially covers participation in domestic and international conferences, such as RubyKaigi and Google I/O.

【職種 / 募集ポジション】
Senior Backend Engineer, ML Platform, Tokyo
【雇用形態】
正社員
【給与】
年収 7,008,000円〜 11,004,000円
Monthly salary system ※Includes fixed allowances for up to 45 hours of legal overtime, legal holiday work, and 40 hours of late-night work.
【勤務地】
108-0023 21F Tamachi Station Tower S, msb Tamachi, 3-1-21 Shibaura, Minato-ku, Tokyo
【Salary System】
<Salary Range> Min 584,000 JPY / month（7,008,000 JPY / year）- 917,000 JPY / month（11,004,000 JPY / year） Each including fixed allowances of 170,064 JPY - 266,988 JPY / month.
【Bonus】
A「High Performance Bonus」may be paid to employees who receive high evaluations based on semi-annual evaluations in addition to their salary. ※Please note that the remuneration of the High Performance Bonus is subject to change according to the company's performance.
【Probation Period】
3 months from join date
【Working Hour System】
Discretionary Labor System for Professional Work ※Conditions apply; subject to change to Flextime System.
【Working Hours】
9:30 - 18:30 (60 min break) are the basic working hours. However, employees are able to choose their working hours at their own discretion. ※There is potential for overtime work outside the determined hours.
【Work Style Policy】
Hybrid work style ・As a standard practice, employees are required to work at the office a minimum of 2 days per week. Employees are encouraged to spend 3 or more days in the office. (This policy may be subject to change based on the company and job circumstances) ・The specific "team office days" may vary depending on the assigned team.
【Holidays/Vacations】
■ Saturdays / Sundays / Japanese national holidays ■ Paid holidays ■ Summer holidays (3 days) ■ Winter holidays (2 days) ■ Year-end and New Year’s holidays (Dec 31st～Jan 3rd)
【Benefits】
■ Various social insurances (employee pension, health insurance, employment insurance, industrial accident compensation insurance) ■ Neighborhood housing allowance and neighborhood moving allowance ■ Health check and gynecological checkup ■ Influenza vaccine ■ Book purchases support ■ Defined-contribution corporate pension ■ Employee stock ownership plan ■ Preferential treatment when using the following services（limited to businesses under contract with Money Forward）　- Rental agency 　- Housekeeping services 　- Babysitting 　- Online English conversation school
【Selection Process１】
Casual interview/Document Screening ↓ First interview (Depending on the position, there may be a technical assignment before the interview.) ↓ Several interviews (The number of interviews depends on the position. We will request you to take an aptitude assessment.) ↓ Final interview (We may ask for a reference check before or after the interview.) ↓ Job offer/Offer meeting ※The process may be subject to change depending on the case.
【Selection Process２】
■ About the Aptitude Test It is a simple web-based survey taking around 20 minutes to complete. ■ What are reference checks? Money Forward may ask for your cooperation with reference checks using a reference check service tool. We believe that mutual understanding is limited to the selection process alone. Therefore, we would like to gather information about you from your supervisor and colleagues at your current or former company to ensure a more reliable match and facilitate your early success after joining our company. ※We do not make employment decisions based solely on the contents of reference checks. ※The fact that you are in the selection process with us will not be disclosed to referees.
【Notes】
- Range of change in job description: Work as determined by the company - Range of change in work location: Work location as determined by the company
【Reference Information】
https://recruit.moneyforward.com/#introduction

会社情報

【会社名】
株式会社マネーフォワード
【代表者】
代表取締役社長グループCEO 辻庸介
【創業】
2012年5月
【取締役】
金坂直哉中出匠哉竹田正信石原千亜希
【社外取締役】
安武弘晃宮澤弦 Ryu Kawano Suliawan 菊間千乃芦田健上田梨々子
【監査役】
畠山優実田中克幸西山茂
【グループCxO・VPox】
上利陽太郎瀧俊雄山田一也坂裕和松岡俊伊藤セルジオ大輔関田雅和松久正幸野村一仁長尾祐美子金井恵子梅田康吉丸山嘉伸
【執行役員】
田平公伸本川大輔冨山直道永井博駒口哲也廣原亜樹島村誠一郎永井七奈木村慎治吉本憲文工藤裕之島内広史小山幸宏渡辺恵伍松村道夫岩崎大渋谷亮
【オフィス】
本社オフィス〒108-0023　東京都港区芝浦3-1-21 msb Tamachi 田町ステーションタワーS 21F 北海道支社〒060-0061　北海道札幌市中央区南一条西4-5-1 札幌大手町ビル3階東北支社〒980-0021 宮城県仙台市青葉区中央2-2-10 仙都会館 5F 東海支社、名古屋開発拠点〒450-6213　愛知県名古屋市中村区名駅4-7-1 ミッドランドスクエア 13F 京都支社、京都開発拠点〒604-8004　京都府京都市中京区三条通河原町東入中島町78番地明治屋京都ビル 4階関西支社、大阪開発拠点〒541-0042　大阪府大阪市中央区今橋 2-5-8 トレードピア淀屋橋 9階広島支社〒730-0015　広島市中区橋本町9-7 ビル博丈5F 九州・沖縄支社、福岡開発拠点〒810-0041　福岡県福岡市中央区大名2丁目6-50　福岡大名ガーデンシティ 16F
【社内コミュニケーション活性化の取り組み】
■全社週次/月次朝会/半期総会 ■代表との意見交換会（CEOセッション） ■全社懇親会（MF Happy Hour） ■他部門社員との交流会（シャッフルランチ・ディナー） ■上長との定期1on1（ツキイチ面談） ■社内公募制度（MFチャレンジシステム） ■社員満足度調査（MFグループサーベイ） ※一部正社員のみ
【労働条件】
屋内原則禁煙（喫煙室あり）等
【中途採用比率】
2021年11月末　93.8％ 2022年11月末　90.0% 2023年11月末　76.6％ 2024年11月末　88.7%

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【Only applicants residing in Japan are eligible to apply.】