【Serverside Engineer(Go)】Hyper-Growth Live Streaming | Full Remote | JLPT N2+

★Server-Side Engineer (toC Service Development)| Music Live Streaming App Business Level Japanese Required (N2 Level) ◆ Fully Remote Work ◆ Start-up Company ◆ 120 days of annual leave ◆ Annual salary: 8 million yen - 15 million yen -------------【About the company】------------- A music live-streaming platform company that develops and operates a song-specific live-streaming app. Featuring a vast music distribution environment utilizing JOYSOUND sound sources and a system where rewards can be earned for each performance, the platform provides a music community where singers and listeners connect. It aims to build an ecosystem that expands the entertainment experience centered on singing and maximizes the power of song. ■Business Overview The company released its song-specific live-streaming app in July 2023. It aims to revolutionize the music domain—where previously only a limited few could succeed—by building an ecosystem where a broader range of singers and peripheral creators can be recognized and earn income. Through this transformation, the company seeks to create a world where people can enjoy music more closely and freely. With investment and business support from XING Inc. (provider of "JOYSOUND") and DeNA Co., Ltd. (operator of "Pococha," one of Japan's largest live-streaming apps), the company's sales are growing at more than double annually, reaching a scale of 360 million yen in monthly sales. The organization is built around a small, elite team primarily composed of members with backgrounds in the live-streaming industry. In 2026, backed by solid product quality and a stable business foundation, the company is aiming for even further growth. -------------【 Job Description】------------- ■Business Overview The company released its song-specific live-streaming app in July 2023. It aims to revolutionize the music domain—where previously only a limited few could succeed—by building an ecosystem where a broader range of singers and peripheral creators can be recognized and earn income. Through this transformation, the company seeks to create a world where people can enjoy music more closely and freely. With investment and business support from XING Inc. (provider of "JOYSOUND") and DeNA Co., Ltd. (operator of "Pococha," one of Japan's largest live-streaming apps), the company's sales are growing at more than double annually, reaching a scale of 360 million yen in monthly sales. The organization has been operated by a lean, elite team primarily composed of members with backgrounds in the live-streaming industry (consisting of 3 executives and external contractors). From 2025, the company will enter a "Growth Phase," aiming for further expansion backed by stable product quality and a solid business foundation. To drive this phase, the company is seeking talented engineers who can spearhead product development. ■Recruitment Background / Business Phase As the company’s song-specific live-streaming app continues its rapid growth, the evolution and stability of the user experience itself have become the core of business expansion. The environment currently demands: ・High-real-time infrastructure capable of withstanding increasing concurrent connections and streaming volume. ・Management of complex APIs and data structures resulting from diversifying user behaviors. ・Architectural improvements to continuously deliver new features at high speed without compromising experience quality. In an environment where traffic spikes and functional expansion occur simultaneously, decision-making at the design level—rather than temporary fixes—directly dictates the speed and upper limits of product growth. Therefore, the company is seeking server-side engineers who can lead design, implementation, and improvement with a deep understanding of existing systems, prioritized for the continued growth of toC products. ■Responsibilities To ensure users can fully enjoy the song-specific live-streaming app, you will be responsible for the design, development, and operation of the backend, with a focus on toC products. ・API Design and Development: Designing and developing Web APIs (REST / gRPC) using the Go programming language. ・Performance and Scalability: Conducting performance tuning and implementing load countermeasures assuming high traffic volumes. ・Database Management: Data modeling, query design, and performance improvement utilizing Cloud Spanner. ・Architecture and Infrastructure: Architectural design and operational improvement on GCP (including GKE and other services). ・Technical Debt Management: Refactoring and resolving technical debt based on an understanding of existing code and specifications. ・System Reliability: Contributing to stable product operations, including incident response and monitoring design. ・Quality Assurance: Enhancing quality through rigorous code and design reviews. ■Development Environment Delivery: Tencent Real-Time Communication Infrastructure: GCP (GKE, Cloud Run, GCS, Pub/Sub), Terraform DB: Google Cloud Spanner Server: Go App: Flutter/Dart Web Frontend: TypeScript, Next.js, React Other: GitHub, Figma, Notion, Slack ■About the Team The engineering team currently consists of 10 members, most of whom are external contractors or side-business professionals. Development is conducted entirely remotely, with nearly all communication taking place via Slack and GitHub. You will work in collaboration with Product Managers (PdMs) and client-side engineers. Additionally, there are dedicated QA and CS teams with whom you will coordinate your operations. -------------【 Requirements】------------- 【Required】 ・Practical experience in Web API development using Go (or experience in backend development using other languages, with the ability to quickly learn Go) ・Experience in database design and operation using RDBMS (e.g., MySQL) ・Practical experience in SQL performance improvement and optimization ・Experience logically organizing business requirements and formulating specifications and designs while considering the impact on existing systems ・Experience in team development using GitHub or similar tools (including code reviews) ・Ability to work independently and take initiative to solve problems beyond one’s assigned role 【Preferred】 ・Experience in developing and operating high-traffic web services ・Experience using Cloud Spanner or distributed RDBMS ・Experience in infrastructure design and operations using GCP (GKE, Cloud Run, etc.) ・Practical experience in performance tuning and load testing ・Experience as a Tech Lead or in a similar technical decision-making role -------------------------------------------------- ■Welfare • Full social insurance coverage • Two-day weekend (Saturday and Sunday) and national holidays • 120 days of annual leave • Fully remote work • Stock options provided -------------------------------------------------------------------------