AI Engineer Internship

Mason - Accelerating development of the built world
Mason is on a mission to accelerate the development of the built world. We are tackling some of the most pressing challenges of our time - housing shortages, energy constraints, and decaying infrastructure - all of which are exacerbated by the slow pace of physical development. This is one of the largest, least-modernized markets in the world.

Trillions of dollars in spending, almost no real software. We create AI employees that are speeding up development for some of the largest REITs, institutional developers, and asset managers in North America. Our founding team comprises of a repeat founder that exited to a Fortune 500, a previous tech lead at Meta SuperIntelligence, and a development director that built $2B+ of projects.

We combine expert services with AI agents so teams can move faster, eliminate errors, and scale with precision. What you’ll build:
Agent-based systems that run long-lived, stateful workflows

Production AI agents that own real developer workflows end to end

Document ingestion and pipelines across PDFs, policies, drawings, and emails

Retrieval, reasoning, and eval layers that improve continuously in production

Secure, multi-tenant infrastructure for enterprise customers

Customer-facing product surfaces in Next.js and TypeScript

Internal tools that let a very small team ship extremely fast

Tech stack and tools:
Frontend: Next.js, TypeScript, modern React

Backend: TypeScript and Python services

AI: Claude, OpenAI, multi-agent systems, structured outputs, eval pipelines

Frameworks: LangGraph, Claude Agent SDKs, MCP tools, emerging agent runtimes

Infra: Cloud-native deployment, CI/CD, monitoring, security-first design

Tooling: Claude Code, Cursor, internal coding agents used daily

We optimize for leverage, learning speed, and systems that actually hold up in production.
What we’re looking for:
High ownership, high agency, own the outcomes not the code

Experience building and shipping AI agents to production

Strong software fundamentals and good systems intuition

Comfort owning infra, deployment, reliability, and security

Familiarity with data processing and document-heavy workflows

Fast learner who actively adopts new tools and frameworks

Customer-obsessed. You care deeply about outcomes

Team and culture:
CEO is a second-time founder who sold his last company to Coinbase

CTO is a former Staff Engineer at Meta Superintelligence and founded Meta AI

COO has led over $2B in real estate development

Backed by top investors, operators, and even major development firms

Working directly with teams managing billions in AUM

Small, intense, low-ego team that genuinely enjoys working together

Regular board game nights, lots of laughs, no corporate nonsense

Remote today, with SF and NYC hubs coming soon

If you want to join a team of winners and re-define the built world - let’s talk :)