Senior/Staff Software Engineer - Backend

About the position

You will be responsible for designing, implementing, and operating the core backend systems for Cotomo and our upcoming new products.

Responsibilities

• Design and implement efficient and highly available infrastructure to support high-volume requests
• Build backend systems that integrate with various AI models including STT, LLM, and TTS.
• Develop streaming systems to enable real-time, high-quality voice conversations
• Construct large-scale data analysis platforms
• Optimize performance and improve scalability of our systems

Tech Stack

Python, Rust, TypeScript, WebSocket, WebRTC, ElasticSearch, PostgreSQL, GCP, Azure, AWS, Unity, Weights & Biases, NVIDIA Triton, vllm, pytorch, transformers, deepspeed, Dataform, BigQuery, Sentry, Slack, Github

Requirements

• 6+ years of experience in designing, implementing, and operating backend systems
• Experience in launching new software products in a leadership role
• Proficiency with relational databases (PostgreSQL/MySQL etc.) and NoSQL databases
• Experience in developing systems that handle large-scale traffic
• Basic knowledge of real-time communication technologies such as WebRTC and WebSocket
• Experience in operating systems on cloud platforms (AWS, GCP, Azure, etc.)
• Experience in developing applications using RAG - personal projects are acceptable
• Conversational Japanese ability

Nice to haves

While not specifically required, tell us if you have any of the following.

• Enthusiasm for learning and applying new technologies to product development
• Ability to think from a user experience perspective and creatively solve technical challenges
• Values teamwork and can communicate openly
• Experience working in early-stage startups (within a few years of founding)
• Experience in operating machine learning models in production environments
• Experience in building and maintaining home server environments
• Experience in training and fine-tuning deep learning models such as LLMs
• Knowledge or experience in speech recognition and natural language processing

Compensation

Starting from 9 million JPY annually, with performance-based stock options.