Full-stack Engineer
Seoul · Hybrid
A senior who can own Next.js 16 · Supabase · TypeScript · Python backend stacks end-to-end into production.
- Next.js 16
- Supabase
- TypeScript
- Python
SONG & STARK RWANDA LTD. · EST. 2023
Seoul · Kigali, one codebase.
Song & Stark Rwanda Ltd. (founded 2023-02-08) keeps local engineers inside the same repos as the Korean HQ — carrying AI pipelines and production infrastructure together. Timezone-overlapping continuous development and dual-office operations by default.
TWO OFFICES, ONE CODEBASE
- HQ · Nonhyeon-ro 152-gil 7
- Seoul
- Subsidiary · Song & Stark Rwanda Ltd.
- Kigali
- Rwanda subsidiary founded
- 2023-02-08
- one codebase, both offices
- Same repo
WHAT WE USE
Tech stack.
Only what actually runs in production today. Experiments are kept off this list.
Frontend
- Next.js 16
- React 19
- TypeScript 6
- Tailwind CSS 4
- shadcn/ui
- next-intl
Backend · Data
- Supabase
- Postgres
- pgvector
- Python
- Go
- Node.js
- Cloud Run
AI
- Voice AI
- 3-Pass LLM
- Whisper / STT
- PyTorch
- OpenAI API
- Claude API
- Gemini
Mobile · Edge
- Expo
- React Native
- Kotlin · Android
- Swift · iOS
- On-device inference
Ops
- Vercel
- GitHub Actions
- Sentry
- Upstash Redis
- Playwright
- Vitest
RECENT SHIPS
What we shipped lately.
Live in production today. Numbers are as they are.
2023–25
Gangwon early-childhood screening system built + SpeechMap engine v2
3-year build of the province-wide screening system (10,000+ users) for the Gangwon Provincial Office of Education. Field insights from that system informed SpeechMap v2, now deployed inside Dururbarun Co-op’s speech therapy program.
2024–25
Dururbarun × KAIST clinical R&D platform
Dururbarun Co-op speech-therapy program live · KAIST faculty co-review · actively maintained.
2024
Sakyung Talk — social-economy community platform
Live on its own domain. Realtime messaging + row-level security.
2024
Korea Self-Reliance Cooperative Federation national platform
National membership management + public-agency dashboards.
2024
Private mid-size client · Android field app
Kotlin · Next.js admin · Supabase. Release cadence compressed.
2026
songstark.com rebrand
AI agents fused into brand, design, content, deployment. 13 brand images generated in a day via Nano Banana 2.
HIRING
We hire only the strongest engineers in each location.
In Seoul and Kigali, we bring on only the top local engineers each city offers. An in-house AI translation and summarization pipeline keeps documentation, code reviews, and standups fully in Korean — so language never blocks two offices from working the same codebase. Open roles are below; if yours isn’t listed but you think you fit, write us directly.
AI Engineer (Voice · LLM)
Seoul · Hybrid
Experience designing voice-analysis engines, LLM pipelines, and RAG systems. Join our in-house patent R&D line.
- Python
- PyTorch
- Voice AI
- LLM Ops
Engineer · Kigali
Kigali · On-site
Engineering team at Song & Stark Rwanda Ltd. Inside the same codebase as the Korean HQ core.
- Full-stack
- React Native
- Python
Seoul · Kigali · remote. Whatever works.
Careers, partnerships, or just a technical chat — whichever. No sales PM in between, the CEO or a core engineer replies directly.