Principal Full Stack Engineer - AI Product

Principal Full Stack Engineer - AI Product

Join the team building an AI-powered platform to transform the $2T engineering services industry! We're creating an intelligent operating system for engineering firms and their customers, using agentic AI to supercharge their talents and build products in hard technology spaces. This is a ground-floor opportunity for a hands‑on technical expert to build the core product features and infrastructure for a high‑potential software product with the support of a parent company leading innovation in engineering and manufacturing.

Who We're Looking For

We're seeking a builder who measures success by shipping high-quality code that solves real customer problems. The ideal candidate has built products from scratch and brings deep expertise across the full stack: from React Native frontends to GCP infrastructure to agentic AI workflows. This role requires already using AI coding tools like Cursor, Copilot, or Claude to 10x productivity, with excitement about building products that bring that same transformative capability to engineering teams.

This principal engineer will work alongside our engineering team, head of product, and AI researchers to build the technical foundations of our platform. The role is hands‑on with code daily while contributing to architectural decisions and helping establish engineering best practices as we grow.

What You'll Do

The first 90 days focus on building initial features for our AI‑powered agents using React Native and modern agentic frameworks while establishing patterns for integrating LLM APIs into production. By month three, core features of our first AI agent ship into pilot testing. Throughout the first year, the role expands to developing product features across web and mobile platforms, implementing real‑time collaboration and workflow automation, and optimizing performance as we scale to 1,000+ users.

Day‑to‑day responsibilities include:

• Building production‑grade React Native applications for web and mobile

• Architecting and implementing cloud‑native services on GCP (Cloud Run, Cloud SQL, Pub/Sub)

• Developing agentic AI workflows using Lang Graph, Lang Chain, or similar frameworks

• Integrating LLM APIs (Claude, GPT‑4, etc.) with proper error handling, streaming, and cost optimization

• Building data pipelines for AI/ML workflows including RAG, vector search, and fine‑tuning

• Writing well‑tested, maintainable code and participating in code reviews to establish engineering best practices

• Contributing to technical architecture and system design discussions with customers to validate and refine features

Technical Requirements

Must Have

• 7+ years building production software, with 4+ years of full‑stack development

• Demonstrated proficiency using AI coding tools (Cursor, Copilot, Claude, etc.) to accelerate development

• Production experience with React Native for web and mobile applications

• Hands‑on experience with GCP services (Compute, Storage, Databases) and deploying containerized applications

• Track record of shipping high‑quality code at scale (10K+ users)

• Strong understanding of system design, API architecture, and database design

• Ability to balance rapid iteration with maintainable, well‑tested code

Highly Valuable

• Experience building agentic AI systems using Lang Chain, Lang Graph, or similar frameworks

• Work with vector databases (Pinecone, Weaviate, Chroma) and RAG architectures

• Background in B2B SaaS platforms or workflow automation tools

• Understanding of engineering, manufacturing, or technical collaboration workflows

• Experience with Dev Ops and MLOps best practices

What We Offer

• Real Impact:
The opportunity to build something that fundamentally changes how engineering gets done

• Customer Access:
Direct exposure to hundreds of real engineering projects annually through Re:

Build companies

• Technical Growth:
Hands‑on work with cutting‑edge AI technologies solving novel technical challenges

• Autonomy:
Backed by Re:

Build while operating with startup independence

• Benefits:
Full health/dental/vision, bonus program, generous 401K, paid time off, annual learning stipend

• Equity & Growth:
Participation in Re:

Build's…