Back End Engineer

Company ProfileEnterprise SaaS provider specializing in contract management solutions that transform how businesses leverage contract data. Post-PMF company experiencing rapid growth, backed by years of proprietary OCR and NLP technology development. The platform serves legal, sales, engineering, and executive teams across major Japanese enterprises, combining battle-tested data digitization expertise with cutting-edge generative AI capabilities. The RoleLead critical technical initiatives from architecture design through implementation and team guidanceOwn technology decisions and code reviews across new feature development, improvements, and operationsDrive performance optimization strategies for contract data processing and full-text search at scaleDesign and implement microservices architecture to support global expansion and feature velocityBuild LLM inference infrastructure that combines massive document processing with generative AIShape technical stack evolution and modernization across the entire platformProvide hands-on technical mentorship to engineering teams while establishing systems that improve code qualityIdentify and solve cross-product technical challenges that impact organizational efficiency Tech Stack: Kotlin, Ktor, Spring Boot, TypeScript, React, Vite, PostgreSQL, Elasticsearch, Google Cloud (Cloud Run, Cloud Functions), GitHub Actions, Splunk Your Skills Required:7+ years building web applications with proven architectural ownershipDeep backend expertise using statically-typed languages (Java, Kotlin, Go, TypeScript)SPA frontend development experience with React, Vue.js, or similar frameworksPublic cloud architecture - designing and operating systems on GCP, AWS, or AzureDDD modeling proficiency and understanding of cloud design patternsRDB design and performance tuning skills for high-volume data processingTechnical leadership experience guiding development teamsBusiness-level proficiency in both Japanese and EnglishValid work authorization for Japan or current Japan residencyPreferred:Large-scale, high-traffic services experienceSRE/DevOps background with microservices architecture designSaaS product launch experience from zero to productionSecurity design and vulnerability remediation knowledge Key Highlights of the Role Post-PMF hypergrowth phase - architect systems that scale from successful product to market-defining platform with massive technical autonomy over technology selection and strategic directionUnique technical challenge - combine proprietary OCR/NLP technology developed over years with cutting-edge generative AI to achieve precision levels generic solutions cannot matchScale-specific challenges - microservices transformation, large-scale LLM infrastructure, and DDD modeling of complex domains at enterprise scaleHands-on + leadership balance - design your own approach between architectural leadership and technical implementation Location Tokyo Salary10 - 19 million yen Reference Number: 06940-0013342172By clicking 'apply', you are deemed to have agreed to Robert Half Japan Privacy Notice (https://www.roberthalf.com/jp/en/privacy). Please ensure that your application documents do not include sensitive personal data such as race, beliefs, medical history, criminal record, or other information irrelevant to hiring process such as spouse or dependents. All information must be accurate and truthful, and any included hyperlinks must be safe and secure.「応募」をクリックすることにより、お客様はロバート・ハーフ（以下、当社）のプライバシー通知（https://www.roberthalf.com/jp/ja/privacy）に同意したものとみなされます。 応募書類には、人種、信条、社会的身分、病歴、犯罪の経歴などの要配慮個人情報や、配偶者、扶養家族など採用選考に無関係な情報を含めないようご注意ください。記載する情報はすべて正確かつ真実であること、また、ハイパーリンクを含める場合には、安全性と信頼性が確保されていることをご確認ください。