• Full-time

Publication date: 2026.11.05

AI Agent Solution Development Engineer [Urgent Hiring] TypeScript / Mastra Experienced (AI Agent Specialization)

  • R&D / Engineer /Technician (AI, Data)
  • Tokyo
  • Salary: JPY 6,000,000 - 12,000,000
AIエージェントソリューション開発エンジニア 【急募】TypeScript・Mastra経験者(AIエージェント特化)
職種Position R&D / Engineer /Technician (AI, Data)
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 Solution Development Engineer, you will lead the design and implementation of AI agents utilizing generative AI and LLMs.
This is a position at the core of technical implementation, turning "research-level cutting-edge technology" into "systems used in real-world settings."
[[Technical areas you will be responsible for]]
・AI Agent / LLM Application Development
Design and implementation of AI agents utilizing LLMs (Claude, GPT, Gemini, etc.).
In TypeScript environments, you will use frameworks such as Mastra, and in Python environments, LangChain / LangGraph, etc., to develop solutions for business automation and decision-support using agent design patterns such as ReAct, Tool Use, Multi-Agent, and MCP.
・RAG / Knowledge Infrastructure Construction
Design and implementation of retrieval-augmented generation (RAG) systems.
Building reliable RAG infrastructure, including vector search, hybrid search, metadata filtering, and evaluation and tuning.
・Workflow Automation and Tool Integration
Design of tool integrations with external APIs, SaaS, and internal systems.
Construction of production-ready workflows, including authorization, guardrail, and audit log design so that agents can carry out actual business tasks.
・LLMOps / Evaluation Infrastructure Construction
Design and implementation of LLMOps pipelines, observability (Langfuse, etc.), and evaluation (LLM-as-a-Judge, offline evaluation, A/B testing).
応募資格Requirement ・Those who can continuously keep up with fast-moving areas such as generative AI, LLMs, and AI agents, and verify them hands-on
・Those who are committed to "not ending at PoC, but running in production"
・Those who enjoy both technical deep dives and adapting to business requirements
・Those who enjoy collaborating with members in diverse roles such as architects, researchers, engineers, and customer-facing staff
・Those with a passion for making Japan and the world better through new technologies
・Those who can empathize with Ridge-i's mission and core values
・Those who take ownership, think and act proactively, 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 6,000,000 - 12,000,000
条件・待遇Condition ・Full weekly holiday system of two days per week (Saturday and Sunday)
・National holidays
・Year-end and New Year holidays (December 28 to January 4)
・Refresh leave (5 days granted after one year of employment)
・Annual paid leave ※10 days, depending on years of service
・Special leave of 3 days before annual paid leave is granted (6 months after joining)
・Career support (patent award bonuses and support for obtaining qualifications) ※
・Learning support (study sessions led by advisors and partner researchers) ※
・Expenses for purchasing 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 listed at the bottom of this page

[Allowances]
・Salary revision once a year (August)
・Bonuses twice a year (January and July)
・Transportation allowance (by the most reasonable route recognized by the company / up to 40,000 yen)
・Overtime pay
[Salary]
Expected annual salary: 6,000,000 yen to 12,000,000 yen
Annual salary system: 6,000,000 yen to 12,000,000 yen ※The above amounts include deemed overtime pay (120,015 yen to 208,080 yen per month / for 45 hours). Overtime beyond this is paid separately. ※Salary amounts are determined by taking into account experience, previous salary, etc. ※Candidates with production development experience in TypeScript × Mastra may be considered for special salary consideration depending on their skills. Offers exceeding the upper limit can also be discussed.
Employment type: Regular employee
[Location]
1-6-1 Otemachi, Chiyoda-ku, Tokyo, Otemachi Building 438
・Directly connected to Otemachi Station on the Marunouchi Line (Exits C7 and E2)
・5-minute walk from JR Tokyo Station
[Working hours]
・Specialized discretionary work system: 8 hours per day
Deemed working hours: 8 hours per day
General office hours: 9:30 to 18:30
・During the probationary period, flextime system applies
Core time: 10:30 to 16:30
Flexible time: Start of work 7:30 to 10:30, end of work 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 the Kanto IT Software Health Insurance Society (use of company-operated welfare facilities is available)
[Passive smoking measures]
Indoor smoking room available
選考についてProcess
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