Senior Software Engineer - Search, AI

Description

We are a fast-growing legal AI company specializing in the development of AI-powered legal tech services. Since our founding in 2017, we have expanded globally and introduced several innovative products, mainly focusing on delivering comprehensive AI legal platforms. Our solutions utilize technologies such as machine learning, natural language processing (NLP), large language models (LLMs), knowledge graphs, and autonomous AI agents to deliver advanced user experiences and robust solutions.

Role Overview

As a Senior Software Engineer in the Search Recommendations Group, you will design, develop, and improve diverse search, recommendation, and agent features supporting multiple fast-growing services. Our search and recommendation platform is a mission-critical part of our product offering, particularly crucial as we integrate advanced LLM-based applications.

You will work with a passionate engineering team and play a key role in defining technology strategies, tackling complex technical challenges, and delivering exceptional search experiences.

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Key Missions & Challenges

• Collaborate with product managers to define search/recommendation infrastructures and agent features that maximize customer value.
• Drive practical and actionable development plans for feature delivery.
• Support team members in designing sustainable and maintainable software systems.

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Responsibilities

• Design, develop, and deliver various search, recommendation, and agent features and APIs.
• Identify and resolve performance and accuracy bottlenecks in LLM-powered applications; expand functionalities that connect search and recommendation features.
• Proactively maintain and operate search/recommendation features.
• Collaborate with team members and cross-functional teams to investigate and set quantitative evaluation metrics for production systems related to search, recommendation, and agent performance, continuously driving improvements.

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Development Environment / Tools

Details available upon request.

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Requirements

• (Requirements unspecified; see Preferred Experience below)

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Preferred Experience

• Master’s or Ph.D. in Computer Science, Mathematics, or similar technical field
• Hands-on experience with Apache Lucene, Elasticsearch, or Solr
• Practical experience developing agent applications, including relevant technologies (e.g., LangGraph, Ragas, LlamaIndex)
• Strong programming skills in Python or Java
• Practical experience in machine learning and natural language processing
• Experience mentoring or educating junior engineers
• Demonstrated leadership experience and strong contribution in large-scale projects (10+ members)
• Proactive in learning and adopting new technologies, especially AI-driven development or productivity tools
• Excellent communication skills and ability to collaborate with teams from diverse cultural backgrounds (fluent in both Japanese and English)

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Working Conditions

Salary

• ¥10,300,000–¥19,000,000 (based on experience and skill)

Location

• Shibuya, Tokyo (on-site location)

Job Type

• Full-time, permanent

Work Hours

• Full-flex system with no core time or discretionary working system applicable
• Overtime may be required
• 1-hour break

Probation Period

• 3 months

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Benefits

• More than 120 annual holidays; full two-day weekends (Saturday and Sunday), national holidays
• Year-end/New Year holidays, annual paid leave (granted upon joining), special leave (sick leave, work-life balance leave, birthday leave), parental/childcare leave, family care leave, condolence leave
• Complete social insurance (health, welfare pension, employment, worker’s compensation)
• Language learning support
• Budget for personal skill development
• Influenza vaccination support
• Non-smoking office (with designated smoking rooms in the building)
• Side jobs allowed (with permission)
• Eruboshi certification (certified for excellence in the promotion of women’s activities)

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*Company information and application forms have been removed as requested.*