Principal Full-Stack Software Engineer

Location: Remote (United States)

Department: Engineering

About the Role

Subquadratic is seeking a Principal Full-Stack Engineer to lead development of our core developer platform, console, dashboards, and customer-facing workflows. You’ll own major architectural decisions, build high-quality product surfaces end-to-end, and partner closely with Product, API, and Research teams to bring new speech + LLM capabilities to customers.

What You’ll Do

• Technical Strategy & Architecture: Drive the future of Subquadratic’s customer-facing stack. From frontend architecture to API design best practices, you’ll make high-impact technical decisions that shape how developers interact with our platform.
• Lead Complex AI Integrations: Architect the full-stack systems required to stream real-time audio and LLM tokens to the browser. You will tackle challenges like handling non-deterministic model outputs, managing WebSocket connections at scale, and visualizing voice-to-text latency.
• Drive Developer Experience (DX): Own the "Time to First Hello World." You will build self-serve onboarding flows, interactive API playgrounds, and observability dashboards that allow developers to debug complex LLM/audio workflows in real-time.
• Own backend systems that power auth, usage, billing, and analytics
• Cross-Functional Partnership: Partner directly with Product and Research leadership to translate experimental AI capabilities into stable, production-ready product features.
• Establish engineering best practices, code quality, and system design standards
• Mentor engineers and guide technical strategy for the product surface area

What You Bring

• Full-Stack Mastery: Deep expertise in TypeScript/React (performance tuning, state management, visualization) and strong backend fluency in Python, Go, or Node.js. You can debug a race condition in the database and a re-render loop in the browser in the same afternoon.
• Platform & API DNA: You have built public-facing APIs, developer consoles, or SDKs. You understand that an API is a product, not just a pipe.
• Proven ability to design scalable architectures and lead complex builds end-to-end
• Systems Expertise: Solid understanding of distributed systems fundamentals—caching strategies (Redis/Memcached), database design (Postgres/DynamoDB), and cloud infrastructure (AWS/GCP).
• Strong product sense and comfort working closely with PM/design

Bonus

• AI/ML Fluency: You don't need to be a researcher, but you understand the constraints of deploying AI: context windows, token streaming, latency budgets, and cost management.
• Experience building real-time media applications (WebRTC, audio streaming, visualization).
• Background in usage metering, billing, or multi-tenant SaaS architectures
• Startup or 0→1 product experience

Success Looks Like

• A polished, reliable developer platform that customers love
• Faster iteration cycles across research → API → product
• Scalable systems and strong engineering foundations for future growth

About the Company

About Subquadratic

Subquadratic is an AI infrastructure and research company building a new class of LLMs on a proprietary post-transformer architecture. While the major labs focus on incremental transformer improvements, we're pushing foundational change at the model architecture level - enabling large-context, multimodal inference that scales efficiently where transformers can't.