Machine Learning Engineer (Search ML)

TL;DR

Machine Learning Engineer (Search ML): Designing and optimizing item search and discovery capabilities for a high-velocity C2C marketplace with an accent on hybrid search, learning-to-rank, and agentic shopping. Focus on bridging the semantic gap between user queries and fragmented UGC while operationalizing advanced LLM architectures.

Location: Hybrid in Tokyo, Japan

Company

hirify.global is a leading C2C marketplace app focused on circulating all forms of value to unleash human potential.

What you will do

• Drive the optimization of item search and discovery capabilities and take end-to-end ownership of core search business logic.
• Design and deploy state-of-the-art ML models and training pipelines, incorporating Hybrid Search, Learning-to-Rank, and Agentic Shopping.
• Develop standardized evaluation and experimentation infrastructure, including offline evaluation frameworks and online A/B testing guardrails.
• Collaborate with infrastructure and product teams to align on scalability, latency, reliability, and cost efficiency.

Requirements

• 3+ years of professional experience in Machine Learning or Search Engineering.
• Proven track record of optimizing search experiences using hybrid retrieval, learning-to-rank, and embedding-based search.
• Hands-on experience with production-grade ML serving infrastructure such as online inference services or feature stores.
• English: Business level or above.
• Strong collaborative and communication skills to align diverse technical teams.

Nice to have

• 5+ years of software engineering experience focusing on large-scale backend architectures.
• Deep technical expertise in distributed systems and high-concurrency/low-latency tuning.
• Japanese language proficiency.

Culture & Benefits

• Full Flextime with no core time.
• Work environment based on principles of Passion For The Product, Growing Together, and Open Collaboration.
• Strong commitment to Inclusion & Diversity.
• Opportunity to solve complex challenges related to high-velocity inventory turnover and UGC semantic bridging.

Hiring process

• Application screening followed by a skill assessment on HackerRank or GitHub.
• Multiple rounds of interviews depending on the position.
• Online reference checks prior to the final offer.