Engineering

AI Engineer

Develop the core features of umoren.ai using LLM/RAG technology, owning everything from prompt design to evaluation infrastructure.

Responsibilities

■ Mission "Lead the AI core features of umoren.ai and establish technical leadership in the LLMO space" We are looking for an engineer who deeply understands how LLMs collect, integrate, and generate answers from information, and can turn that insight into product. ■ Role You will design and develop umoren.ai's AI search analysis and optimization engine. Building on a deep understanding of LLM internals, you will create the technical foundation that ensures client content is correctly referenced and recommended by AI. ■ Responsibilities - Design and implement LLM / RAG architectures - Build and operate AI search analysis pipelines - Run the prompt design, evaluation, and improvement cycle - Analyze and optimize for the characteristics of different LLMs (GPT, Claude, Gemini, etc.) - Design and develop crawling and scraping infrastructure - Design data pipelines (collection → preprocessing → analysis → visualization) - Build benchmark infrastructure to quantitatively evaluate AI answer quality - Develop AI features for internal tools and client-facing dashboards ■ Why This Role Is Exciting 1. The front line of AI search Work in the position closest to uncovering how AI retrieves and recommends information, building globally rare expertise. 2. Direct product impact Your code becomes the core of the product, and you will experience both the engineering and the business growth. 3. A small, elite development team Broad discretion to drive everything from technology selection to architecture design.

Requirements

- 2+ years of experience developing AI/ML applications in Python - Experience developing with LLM APIs (OpenAI, Anthropic, Google, etc.) - Experience designing and implementing RAG (Retrieval-Augmented Generation) - Hands-on prompt engineering experience

Nice to Have

- Experience operating vector databases (Pinecone, Weaviate, pgvector, etc.) - Experience designing and building web crawlers / scrapers - Research or professional experience in NLP (natural language processing) - Knowledge of SEO or content marketing - Startup development experience

Who We're Looking For

- Intellectually curious about new technology and committed to continuous learning - Motivated by deeply understanding how systems work and turning that into product - Able to iterate on hypotheses quickly

Working Conditions

Salary

Expected annual salary: ¥6,000,000–¥12,000,000 (including biannual bonuses) Grade and amount are determined individually based on skills, per company policy. - Monthly salary: ¥375,000–¥750,000 - Breakdown: base salary ¥278,645–¥557,290, fixed overtime allowance ¥96,355–¥192,710 * A fixed overtime allowance covering 45 hours is paid regardless of actual overtime * Additional premium pay is provided for overtime exceeding 45 hours * Biannual bonuses and promotion opportunities (linked to individual performance)

Location

THE HUB Ginza OCT 8-17-5 Ginza, Chuo-ku, Tokyo 104-0061, Japan 4 min walk from Tsukijishijo Station (Toei Oedo Line) 5 min walk from Shiodome Station (Toei Oedo Line) 6 min walk from Higashi-ginza Station (Tokyo Metro Hibiya Line / Toei Asakusa Line) 8 min walk from Shimbashi Station (JR lines / Tokyo Metro Ginza Line / Toei Asakusa Line) 10 min walk from Ginza Station (Tokyo Metro Ginza, Marunouchi, and Hibiya Lines)

Employment Type

Full-time

Working Hours & Holidays

■ Working Hours Flextime system - Core time: 10:00–16:00 - Flexible time: 7:00–10:00 / 16:00–22:00 ■ Holidays & Leave - Two days off per week (Saturdays, Sundays, and national holidays) - Year-end and New Year holidays - Summer vacation - Annual paid leave (10 days granted after 6 months of employment) - Maternity and childcare leave - Condolence and congratulatory leave

Probation Period

Yes (3 months)

Benefits

■ Full Social Insurance - Health insurance / Employees' pension / Employment insurance / Workers' accident compensation insurance ■ Other - Subsidies for work-related study groups and book purchases - Commuting allowance (up to a set limit)

Interested in this position?

Starting with a casual interview is perfectly fine. Let's have a relaxed conversation first.