AI Application Engineer

Date PostedJune 9, 2026LocationTokyo (Shinagawa), Hyogo (Kobe), JapanCompanyDejimal IncSalaryJPY 6000K - JPY 12000KTypeit (pc, web, unix) - web application se

Job Summary

The Application Engineer will design and implement development 'harnesses' to enable generative AI to produce high-quality, consistent output. This role focuses on structural improvements, including prompt design, automated testing, and CI/CD workflows, to enhance overall team productivity. You will be responsible for building automated PR flows and establishing standardized development processes within a growing SaaS environment.

Responsibilities

  • Design and implement AI-driven development harnesses
  • Build automated PR flows and testing pipelines
  • Standardize AI prompt structures and review criteria
  • Improve team productivity through structural optimization

Required Skills

  • Experience as Tech Lead or Engineering Manager
  • Agile/Scrum team management expertise
  • Web application full-stack development skills
  • Backend API and database design experience

Job Details

### Job Description In this role, you will transition development systems to leverage generative AI, focusing on designing 'structures (harnesses)' that allow AI agents to function effectively at a practical level. This includes: - Designing AI input (context/prompt structure). - Automating output verification and testing. - Standardizing review criteria. - Designing feedback loops to handle failures. ### Core Responsibilities - Designing the AI-based code generation process. - Building an automated PR generation flow. - Designing automated testing and QA protocols. - Improving review workload and reducing lead times. - Increasing team productivity through structural improvements. ### Expected Outcomes (First 6 Months) - Establish an automated PR generation flow for a functional theme. - Standardize AI input templates and context design. - Implement automated test generation and verification loops. - Achieve quantitative improvement in review load and lead time. - Develop reusable harness design documentation. ### Job Requirements - Experience as a Tech Lead, Engineering Manager, or equivalent leadership role. - Proven experience in team development (Agile, Scrum) from specification to delivery. - Experience designing backend APIs and databases for web applications. - Implementation expertise across web frontend and backend. ### Preferred Skills - Development experience in Go or Ruby. - Development experience with B2B services or SaaS. - Ability to thrive in a challenging and chaotic growth environment. ### Working Hours & Benefits - Working Hours: 9:30 AM - 6:30 PM (1-hour break). - Overtime: Average 30 hours or less per month. - Salary Revision: Once a year. - Bonus: Twice a year based on performance. - Allowances: Commuting (full), Remote work (10k/month), Neighborhood (20k-30k/month). - Insurance: Comprehensive social insurance and company-funded group medical insurance. - Leave: 122 Annual Holidays, including paid leave, illness leave, and special '1000-day' leave. - Development Support: Annual book/seminar subsidy (100k/year) and e-learning access.