• Full-time

Publication date: 2026.11.05

AI Agent Application Development Engineer [Urgent Hire] Full-Stack × AI Application Development for Specific Business Functions (Especially TypeScript / Mastra)

  • System Engineers / Infrastructure Engineers / Web Engineers / Game Developers
  • Tokyo
  • Salary: JPY 7,000,000 - 13,000,000
AIエージェントアプリケーション開発エンジニア 【急募】フルスタック × 特定業務特化AIアプリ開発(特にTypeScript・Mastra)
職種Position System Engineers / Infrastructure Engineers / Web Engineers / Game Developers
会社概要Company profile "We aim to realize a new society by tackling unsolved challenges using cutting-edge technology and business insight powered by data and AI," is our Mission. Through dialogue with partner companies, we propose and build optimal systems that combine various technologies, realizing DX as a solutions company.
"Providing top-tier solutions that pursue both technical excellence and business impact, solving business and social challenges, and creating a new society."
Since its founding, the company has aimed to maximize the interaction between technological innovation and business, providing value to society. In 2023, in the 7th year after its founding, it listed on the TSE Growth Market and continues to grow both in Japan and overseas. Together with team members with diverse areas of expertise, it integrates technology and business and is recognized for its commitment to pursuing customer success and impact on society.
The company is a tech innovation firm that tackles management and social challenges through solutions using AI and deep learning technologies. In particular, it has strengths in "multimodal AI," which combines AI that handles various types of data, such as image analysis deep learning, sensor-based anomaly detection AI, and optimization AI. Starting from strategy formulation and requirements definition, it accompanies clients end-to-end, from on-site consulting to development and operation and maintenance, until they experience return on investment. It has achieved many results, including automation of waste incineration plant operations. The company also actively addresses social challenges, and has won the 4th and 5th Space Development and Utilization Awards consecutively, including for "GRASP EARTH," which discovers SDGs challenges and environmental changes from satellite imagery.
Going forward, we will continue to pursue excellence in technology and business, providing top-tier solutions that allow society and customers to sustainably experience their effects.

[Company Highlights]
・Fundamental DX projects with top-tier clients in the industry
・You can work on DX projects with leading companies aimed at solving industry and management challenges.
・Growth as a talent who integrates business and technology
・This is an environment where you can learn and grow toward becoming a integrated talent with strengths in both business and technology. In fact, graduates are active at Big Tech companies such as Meta, Google, and Amazon.
・Diverse culture and improvement of English skills
・You can work in a multinational environment where global engineers make up about 55%, and your English skills will also improve through projects.
・Utilizing the latest technology
・You can gain hands-on experience while applying cutting-edge digital tools and technologies in your daily work.
・Emphasis on solving social challenges and ethical conduct
・The company culture encourages seriously considering and acting on solutions to social challenges and ethical behavior.
・Working with excellent colleagues
・Many employees who have joined say "the colleagues are great," and this is an environment where you can work with trustworthy team members.
仕事内容Job description As an AI Agent Application Development Engineer, you will develop AI applications specialized for specific customer operations, full-stack from front end to back end,
You will be responsible for building "AI applications that customers continue to use in their actual operations," covering everything from requirements gathering, UI design, API implementation, LLM integration, and deployment to operations,
This is a position at the forefront of customer contact.
[[Technical areas you will be responsible for]]
- Front-end development for AI agent applications
Design and implementation of AI agent chat UIs, dashboards, and operational screens using TypeScript / React / Next.js, etc.,
Streaming display of LLM output (Server-Sent Events), real-time updates,
Interaction design that optimizes user experience.
- Development of back-end APIs and integration layers
Implementation of LLM integration APIs, business logic, authentication and authorization, and external system integration using Node.js / TypeScript, etc.,
Building production-ready AI agent functionality using frameworks such as Mastra in TypeScript environments and LangChain / LangGraph in Python environments.
- Understanding business requirements and reflecting them in solutions
Deeply understanding customers' business flows and how end users work, and reflecting them in the UI/UX and functional design of AI applications.
Building consistently from the foundation to operational screens in collaboration with solution development engineers.
- Executing production operation and improvement cycles
Responsible for deployment, operational monitoring, usage analysis, and improvement proposals.
Taking responsibility for growing the application together with customers.
応募資格Requirement ・Those who continuously keep up with fast-moving areas such as generative AI, LLMs, and AI agents,
and can validate them hands-on
・Those who are committed to "not ending at PoC, but running in production"
・Those who are committed to building
"apps that users truly want to use"
・Those who want to broaden their scope without limiting themselves to a specific area, such as frontend, backend, or LLM integration
・Those who enjoy collaborating with members in diverse roles, such as architects, researchers, engineers, and customer representatives
・Those with a passion for making Japan and the world better through new technologies
・Those who empathize with the Ridge-i mission and core values
・Those who take ownership, think proactively, act, and keep going
日本語力Japanese level Native
雇用形態Employment type Full-time
勤務エリアLocation Tokyo
勤務時間Working hours —
想定年収Salary JPY 7,000,000 - 13,000,000
条件・待遇Condition ・Full two-day weekly holiday system (Saturday and Sunday)
・Public holidays
・New Year holidays (December 28 to January 4)
・Refresh leave (5 days granted after one year of employment)
・Paid annual leave※10 days, depending on years of service
・Special leave of 3 days before paid annual leave is granted (after 6 months of employment)
・Career support (patent bonuses and qualification acquisition support)※
・Learning support (study sessions led by advisors and partner researchers)※
・Expenses for books and necessary equipment (monitors, e-learning such as Udemy, etc.)※
・Healthcare support (external consultations and free acupuncture treatment)
・All beverages, nutritional supplements, and snacks are free of charge
・Communication support, etc.
※Details are described below on this page.
[Various allowances]
・Salary revision once a year (August)
・Bonuses twice a year (January and July)
・Transportation allowance (route the company deems most reasonable / up to 40,000 yen)
・Overtime allowance
[Salary]
Expected annual salary: 700万円〜1,300万円
※Includes deemed overtime pay (140,018円 to 225,420円 per month / for 45 hours). Overtime exceeding this amount will be paid separately. ※For those with production development experience using TypeScript × Mastra, special consideration in terms of salary will be considered according to skill level. Proposals exceeding the upper limit can also be discussed. 《Bonus》 Based on basic monthly salary, bonuses in amounts determined by company performance are paid twice a year.
Employment type: Full-time employee
[Work location]
Tokyo, Chiyoda-ku, Otemachi 1-6-1 Otemachi Building 438
・Directly connected to Otemachi Station on the Marunouchi Line (Exits C7, E2)
・5-minute walk from JR Tokyo Station
[Working hours]
・Specialized discretionary work system, 8 hours per day
Deemed working hours: 8 hours/day
General office hours: 9:30 to 18:30
・During the probation period, flextime system applies
Core time: 10:30 to 16:30
Flexible time: start 7:30 to 10:30, end 16:30 to 20:30
Break time: 1 hour between 11:00 and 16:00
[Social insurance]
Insurance: Health insurance, employees' pension insurance, employment insurance, workers' accident compensation insurance
Health insurance: Enrolled in Kanto IT Software Health Insurance Society (use of company-operated recreational facilities, etc., available)
[Secondhand smoke prevention]
Indoor smoking room available
選考についてProcess
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