Founding Full‑stack Engineer (NYC)

Founding Full Stack Engineer

We're building our foundational NYC engineering team from scratch and looking for exceptional builders who are resourceful, deeply technical, and thrive in high-ownership environments. As one of the first in-house engineers, you'll shape the core of our platform and the culture of a team that will scale to 20+ over the next 18 months. You'll build and orchestrate AI agents, pioneer new UX paradigms, and tackle some of the hardest problems in applied AI with autonomy and end-to-end ownership.

Business Impact | What you will own…

• Own 0→1 and 1→N features across the stack, from design docs to building high-throughput data pipelines and scalable FastAPI services.
• Architect and own the core agent orchestration engine, designing complex, multi-agent LLM workflows (routing, tool-use, memory, evaluation) with deterministic fallbacks, guardrails, and auditable actions required by enterprise users.
• Build AI-native, human-in-the-loop UIs. Craft React/Next.js interfaces that let users collaborate safely with agents, with transparency and explainability by design.
• Develop the "factory for the factory". Build our experimentation platform: CI/CD for prompts and agents, offline/online evals, drift detection, safety layers, and rollout controls.
• Ship fast, safely. You'll instrument everything for reliability, write concise design docs, add robust tests, and build dashboards and alerts for features you launch.
• Partner cross-functionally with Product, AI, Design, CS; talk to customers and SMEs, and turn ambiguous problems into shipped product.
• Obsess over performance, optimizing for latency across the system: caching, model selection, distillation, batching, vector search, and infrastructure efficiency (GPU/CPU).
• Operate what you build. This includes on-call ownership, leading incident response, and driving learning through blameless postmortems.

Our Stack

• Frontend: React, Next.js
• Backend: Python, FastAPI
• Data/ML: MongoDB, S3, Redis; Pinecone
• Infra: AWS, Docker, Kubernetes; CI/CD with GitHub Actions
• Messaging: SQS; event-driven pipelines

This role is for you if...

• You're a 0 → 1 builder who thrives in ambiguity and has shipped products from scratch at a startup or in a hyper-growth phase. You've seen both - early-stage hustle and later-stage scale and know how to build for it.
• You're a systems thinker with deep technical chops: you design clear architectures and write clean, tested Python and TypeScript.
• You think like an owner: you spot problems, propose solutions, and build them without waiting for perfect specs. Your impact is measured in business outcomes.
• You use AI as leverage. Tools like Cursor, Copilot, or Claude Code are integral to your workflow, helping you ship faster while maintaining a high standard for correctness.
• You believe speed and quality aren't opposites and can articulate the tradeoffs you make.
• You communicate crisply. You share your ideas effectively and thrive in tight feedback loops with product, design, and customers.
• You've got grit: hard problems energize you, context switching doesn't scare you, and you're comfortable deleting code.

This role is NOT for you if...

• You see a hard line between "frontend," "backend," and "product."
• You are uncomfortable with ambiguity, rapid context-switching, and dynamic priorities.
• You are looking for a predictable, 9-to-5 role.

Required Skills & Experiences

• Experience with LLM/agent systems, evals, and prompt tooling; RAG, embeddings, vector dbs.
• Deep knowledge of event-driven systems, streaming, and workflow engines.
• Expertise in observability (OpenTelemetry/Prometheus/Datadog), feature flagging, or A/B platforms.
• Background in enterprise security and compliance (SOC 2, GDPR)
• Bias to action: short specs, small PRs, daily deploys.
• In-person collaboration: we're building the NYC hub together; whiteboards > long threads.
• High ownership: you'll touch product, talk to customers, and influence the roadmap.

Benefits

Upon joining the Knit team in this foundational role, you will receive a competitive salary, Equity Options, Healthcare (medical, dental, and vision), and Additional Coverage, a company laptop and one-time, onboarding Technology Stipend, a 401(k) with company match, flexible time-off, hybrid working, and more!