Full Stack AI Engineer

Constella Care; United States; Remote; USD 120,000 - 180,000; Full time

Job summary

Infinity is assembling an AI-native engineering team to build agent-driven products. We focus on rapid prototyping of AI applications, LLM workflows, and full-stack features across our portfolio companies.

As a contract-to-hire engineer, you’ll work on fast-moving projects, validating ideas in short sprints and scaling production tools. Remote role with EST-friendly hours and a path to full-time within the core team.

Qualifications

• Fluency in Python and experience with AI toolkits and APIs.
• Experience rapidly building and iterating on proofs of concept or MVPs.
• Comfort using a blend of commercial APIs, open source, and low-code tooling.
• Strong problem-solving skills and analytical intuition.

Responsibilities

• Build working prototypes of agentic AI applications, LLM workflows, and full-stack products.
• Experiment quickly across frameworks, open source tools, and low-code stacks.
• Interface directly with product thinkers and founders to distill ideas into testable code.
• Contribute to shared internal libraries and feature Gravity, our software factory platform.
• Occasionally embed with portfolio companies to support launches or unblock execution.

Skills

Python

POC/MVPs

APIs & AI

Frontend basics

Tools

LLM frameworks

Job description

AI Engineer (Contract-to-Hire)

Location: Remote (Global, EST working hours)
Start Date: Rolling

About The Project

We're building AI-native engineering team within Infinity, a holding company building full-stack AI businesses. We support portfolio companies by:

• Rapidly prototyping new product ideas to validate markets

• Providing flex capacity during high-growth phases

• Maintaining and evolving the Gravity our in house software factory and agent hub that we use to build all software.

We’re not a dev shop. We’re a surgical team of builders who move fast, reduce ambiguity, and create leverage across a network of founders building with AI at the core.

The Role

We’re looking for scrappy, sharp, execution-focused engineers who thrive in high-autonomy environments. You'll be deployed on fast-moving projects; from validating ideas in one-week sprints to helping scale production tools inside early-stage companies.

This is a contract-to-hire role. If there’s mutual fit, you’ll transition to a full-time or retainer-based role within the core team.

What You’ll Do

• Build working prototypes of agentic AI applications, LLM workflows, and full-stack products

• Experiment quickly across frameworks, open source tools, and low-code stacks

• Interface directly with product thinkers and founders to distill ambiguous ideas into testable code

• Contribute to shared internal libraries and the Infinity Commons and add features to Gravity, our software factory platform.

• Occasionally embed with portfolio companies to support launches or unblock execution

What We’re Looking For

Required:

• Fluency in Python and experience using AI toolkits and APIs

• Experience rapidly building and iterating on proof-of-concept or MVPs

• Comfort using a blend of commercial APIs, open source, and low-code tooling to get things done

• Strong problem-solving skills and analytical intuition

Bonus Points:

• Prior work with AI agents, and a deep familiarity with what it takes to make them work well in production environments.

• Experience with frontend development (React, Next.js, etc.)

• A background in a STEM discipline, data science, or quant-heavy engineering you'll need to be able to show the impact of your work with statistical significance

• Previous experience in a venture-backed startup or technical founder role

How We Work

• Asynchronous by default, with tight feedback loops and clear ownership

• High-trust, high-autonomy culture that values shipping, learning, and iterating

• Small, elite team of senior builders with experience across AI, product, and infrastructure