Full Stack Engineer for English Speaker

Position Overview

Mico is looking for a Lead Full Stack Engineer to lead the development of Mico Message, an AI-native customer engagement platform. This role spans both frontend and backend engineering. Beyond hands-on development, you will drive architecture and technical decisions, improve engineering practices and production operations, mentor engineers, and help shape the product's technical direction.

Key Responsibilities

• Lead the design and development of scalable frontend and backend systems supporting Mico Message.
• Build and improve customer-facing applications and internal operational tools.
• Design robust APIs, backend services, and integrations with external platforms.
• Drive technical decisions and contribute to system architecture discussions.
• Partner closely with Product, Design, AI, and Infrastructure teams to shape product direction and user experience.
• Continuously improve system reliability, scalability, performance, and operational visibility.
• Write maintainable, well-tested code and promote modern engineering practices.
• Establish and improve engineering standards, development workflows, and technical processes.
• Mentor and support engineers through code reviews and technical guidance.
• Investigate and resolve complex production incidents in distributed systems.
• Communicate and collaborate with cross-functional stakeholders in both Japanese and English.
• Take end-to-end ownership from requirements definition through production deployment and operations.

Technology Stack

• Application: TypeScript / Node.js (monorepo)
• Databases: Aurora MySQL, TiDB, and Aurora PostgreSQL for some services
• Data warehouse: Snowflake
• Cloud: AWS

Required Qualifications

• At least 5 years of professional software engineering experience.
• Experience working with Agile and Scrum development processes.
• Business-level or higher English proficiency and conversational Japanese proficiency.
• Strong full stack development experience building modern web applications.
• Frontend development experience with React, Vue, Next.js, or similar frameworks.
• Backend development experience with Node.js, Python, Elixir, Ruby, PHP, or similar technologies.
• Experience designing scalable APIs and backend systems.
• Strong understanding of software architecture, system design, and technical trade-offs.
• Experience with relational databases such as PostgreSQL or MySQL.
• Experience developing and operating systems in production, with operational responsibility.
• Experience mentoring engineers or leading technical projects.
• Strong communication, debugging, collaboration, and problem-solving skills.
• Ability to proactively drive work and solve problems in uncertain environments.

Preferred Qualifications

• Experience with typed languages and tools, such as TypeScript or Python type hints.
• Experience with gRPC and Protocol Buffers.
• Experience with Elixir/Phoenix or functional programming.
• Experience developing scalable SaaS platforms.
• Understanding of conversational AI or applications powered by large language models (LLMs).
• Experience designing event-driven architectures or distributed systems.
• Experience collaborating closely with Infrastructure or DevOps teams.
• Experience improving engineering processes and workflows.
• Experience at a fast-growing startup or interest in AI-assisted software development workflows.