Founding Technical Leader (CTO/Founding Engineer), NewCo at 25madison Llc

Job description

Founding Technical Leader: Head of Engineering / CTO Company: Newco (Stealth) Role: Head of Engineering / Founding Engineer (Full-Time) Location: Flexible (US, preference for NYC) S tage: Pre-seed (Venture Studio backed) Comp: Significant equity + competitive cash Who We Are Commerce is undergoing a fundamental shift. For the past decade, ecommerce has been built around static pages, manual optimization, and fragmented tooling: from analytics to experimentation to personalization. Newco is building the AI-native intelligence layer for DTC commerce. Our platform interprets shopper behavior from the moment of ad click, scores intent in real time, and dynamically personalizes the on-site experience without requiring brands to rebuild their infrastructure. Every interaction compounds: the system learns, adapts, and improves outcomes continuously. The result: higher conversion, stronger retention, and a lasting edge for brands competing in a signal-scarce, AI-native world. What You'll Do • Define system architecture from first principles and own it end-to-end • Build the initial product hands-on (this is a 0 to 1 role) • Design and scale the decisioning and personalization engine across data, infra, and product layers • Work directly with the founder on product direction and technical strategy • Hire and lead the early engineering team as the company grows • Communicate technical tradeoffs and system design to non-technical stakeholders in outcome-oriented terms Who You Are • A builder-leader at the intersection of AI, product, and real-time systems • Experienced in high-stakes, fast-moving environments: vertical SaaS, applied ML, or personalization/recommendation systems • Comfortable working across backend, frontend, and product, not siloed • Strong product intuition alongside technical execution • Thrives in ambiguity and early-stage building Key Technical Responsibilities • Decisioning and Personalization Architecture Design and scale the real-time scoring and routing engine: interpreting incomplete behavioral signals, making decisions under uncertainty, and serving personalized experiences with low latency. • LLM and Agentic Systems Build and maintain AI agent layers using frameworks like LangGraph or PydanticAI, including modular reasoning pipelines (RAG, ReAct, planner-executor) for CRO automation and content decisioning. • Data Infrastructure Integrate event-driven pipelines, vector databases (pgvector, Pinecone), and structured data stores to support real-time retrieval, persistent memory, and behavioral pattern recognition. • Evaluation and Observability Build tools for trace inspection, confidence scoring, and output validation. Develop evaluation loops and test harnesses to ensure reliability and consistency across decisioning outputs. • Engineering Architecture and Delivery Define technical standards, development processes, and system architecture to support a scalable, maintainable product. Partner with product leadership to translate strategy into roadmap. Core Skills • 5 to 7+ years of full-stack engineering experience • Experience building real-time systems, data pipelines, or decisioning / recommendation engines • Familiarity with LLM agent development and frameworks (LangGraph, PydanticAI, or similar) • Production-level experience with FastAPI, Docker, and cloud-native deployment • Comfort with vector databases and retrieval-augmented generation patterns • Proficiency in agentic IDEs (Cursor, Windsurf, Claude Code) Bonus (not required) • Experience in ecommerce, marketplaces, or personalization platforms • Familiarity with event-driven or streaming architectures (Kafka, Kinesis) • Shopify ecosystem knowledge What This Is Not • Not a pure infrastructure or platform role • Not a maintenance or scaling role • Not joining a large existing team You will be building the foundation. Why Join • Significant equity + competitive cash • True technical ownership: define the system architecture from day one • Backed environment: venture studio with capital, operational support, and design partners already in market • 0 to 1 opportunity: build a company, not just write code

Requirements

Must-haves

Founding Technical Leader: Head of Engineering / CTO Company: Newco (Stealth)
Role: Head of Engineering / Founding Engineer (Full-Time)
Location: Flexible (US, preference for NYC)
S tage: Pre-seed (Venture Studio backed)
Comp: Significant equity + competitive cash
Define system architecture from first principles and own it end-to-end
Build the initial product hands-on (this is a 0 to 1 role)
Design and scale the decisioning and personalization engine across data, infra, and product layers
Work directly with the founder on product direction and technical strategy
Hire and lead the early engineering team as the company grows
Communicate technical tradeoffs and system design to non-technical stakeholders in outcome-oriented terms
A builder-leader at the intersection of AI, product, and real-time systems
Experienced in high-stakes, fast-moving environments: vertical SaaS, applied ML, or personalization/recommendation systems
Comfortable working across backend, frontend, and product, not siloed
Strong product intuition alongside technical execution
Thrives in ambiguity and early-stage building
Key Technical Responsibilities
LLM and Agentic Systems Build and maintain AI agent layers using frameworks like LangGraph or PydanticAI, including modular reasoning pipelines (RAG, ReAct, planner-executor) for CRO automation and content decisioning.
Data Infrastructure Integrate event-driven pipelines, vector databases (pgvector, Pinecone), and structured data stores to support real-time retrieval, persistent memory, and behavioral pattern recognition.
Evaluation and Observability Build tools for trace inspection, confidence scoring, and output validation. Develop evaluation loops and test harnesses to ensure reliability and consistency across decisioning outputs.
5 to 7+ years of full-stack engineering experience
Experience building real-time systems, data pipelines, or decisioning / recommendation engines
Familiarity with LLM agent development and frameworks (LangGraph, PydanticAI, or similar)

Nice-to-haves

Bonus (not required)

Application prep

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