About OnSite

OnSite is the messaging platform replacing WhatsApp for teams in the built environment. We take field chaos and turn it into real-time collaboration — making work better for the people on the ground and the teams managing them. Backed by Tin Men Capital, Alter Global, Hustle Fund and Gondor Capital.

Why this is exciting

Construction is a $2T industry that's been underserved by software for decades. You'll be working on a mission-driven, user-focused product that solves real problems for real people — on a small, laser-focused team where your work ships fast and matters immediately.

About the Role

We're looking for an experienced Backend Engineer to own and evolve the core systems powering OnSite. You'll work on a modern serverless architecture to deliver the real-time collaboration tools that keep frontline teams connected.

What we're looking for technically

You're proficient in building backend systems and can work across our stack:

• Excellent system design skills
• Proficient in TypeScript and Python
• Deep expertise in AWS serverless development (Lambda, API Gateway, RDS, Step Functions, etc.)
• Strong experience building and optimizing RESTful APIs and event-driven architectures
• Solid understanding of MySQL and Elasticsearch
• Comfortable integrating third-party APIs (Auth0, Jira, Sendbird, etc.)

Nice to haves:

• Experience building for blue collar industries, project management, or collaboration tools
• Familiarity with real-time messaging and notification systems
• Knowledge of task tracking and project management concepts
• Comfortable using AI tools as a natural part of your workflow

What matters more than any of this