Senior Software Engineer

Job Title: Senior Software Engineer

Location: Full-remote

Employment Type: Full-time (Regular Employment)

Salary: 6,000,000~12,000,000 JPY

Open for applicants who is currently residing in Japan with valid working visa for non-Japanese citizen

About the Company:

This fast-growing tech startup provides AI-powered sales enablement SaaS that analyzes voice conversations to improve communication in sales and customer success. Founded in 2017 and based in Shibuya, it now has over 210 members and operates fully remotely with flexible work styles.

Its core products include AI-driven IP phone systems and real-time conversation analysis tools, all developed in-house—from recording and transcription to emotion analysis. These solutions integrate with CRMs and help companies boost efficiency and decision-making.

The company holds the No.1 market share in Japan for cloud-based conversational AI and topped Deloitte’s 2022 Technology Fast 50 Japan with 486.7% growth. Over 10,000 companies use its platform, with more than 250 million voice recordings accumulated.

A key advantage is its highly accurate proprietary speech recognition engine (90%+), optimized specifically for Japanese business workflows—delivering reliability and adoption unmatched by overseas products.

Your Role

This position is responsible for designing, implementing, and optimizing multimodal AI systems centered around voice, with the goal of creating new forms of communication that connect people through shared experiences. Leveraging cutting-edge machine learning models, the successful candidate will engage in the following areas:

• Lead the design and implementation of architecture for large-scale distributed systems, with a focus on improving reliability and scalability

• Build efficient and cost-effective infrastructure using cloud-native technologies

• Design and implement advanced MLOps pipelines to support continuous model improvement and rapid deployment

• Develop real-time data processing and analytics platforms to enhance business intelligence

• Collaborate with research and development teams specializing in next-generation AI to prototype and productize innovative features

• Design high-availability, low-latency system architectures in anticipation of global expansion

［Key Attractions］

• Opportunity to contribute to the early-stage practical implementation of cutting-edge multimodal AI technologies in the B2B space

• Work in close collaboration with a research and development team that presents at international conferences and publishes academic papers

• Gain hands-on experience in large-scale development, handling over one million analysis requests per day

• Acquire expertise in real-time data processing technologies such as Amazon Kinesis

• Obtain experience in designing and implementing MLOps pipelines for large-scale systems

• Take an active, autonomous role in development while collaborating with senior engineers

［Technology Stack (Including Planned Technologies)］

The team is advancing a microservices architecture for real-time services and analytics, selecting optimal technologies tailored to the characteristics of each service.

• Backend: Python (Django), Elasticsearch

• Frontend: React.js, Vue.js

• Data Analysis: Python, TensorFlow, Keras, PyTorch

• Communication: SIP, VoIP, WebRTC, WebSocket

• Infrastructure: AWS, Google Cloud, Terraform

• Mobile Applications: Kotlin, Swift, Flutter (Dart)

• Communication Tools: Slack, GitHub, Confluence

Requirements:

Must-Have:

• Over 3 years of experience developing distributed systems on cloud platforms, particularly AWS
• In-depth knowledge and hands-on experience with container orchestration technologies such as Kubernetes
• Proven experience in designing and implementing CI/CD pipelines to automate development processes
• Advanced programming skills in Python or a comparable language
• Experience in cost optimization and performance tuning for large-scale systems

Nice-to-Have:

• Experience in designing and implementing machine learning systems
• Practical experience in speech processing or natural language processing
• Background in developing multimodal AI applications
• Experience in designing and implementing microservices architecture
• Experience with serverless architecture design and implementation
• Hands-on experience with large-scale data processing technologies such as Apache Spark or Kafka
• Experience in developing cloud-native applications
• Track record of contributions to open-source projects
• Conversational-level English proficiency or higher (English is used in team meetings)

Perks & Benefits:

• Flextime with no mandatory core hours
• Full transportation cost coverage (if visiting office occasionally)
• Health insurance
• Weekends and national holidays off
• End of year and New Year holidays
• Trial period: 6 months (standard)

We have more positions available—if you're open to new opportunities, don’t hesitate to apply!

Job ID: 06521