# Senior Platform Engineer at JustAI

- Company: JustAI (YC W24)
- What the company does: Agentic Marketing Platform. Backed by Peak XV and Y Combinator.
- Company website: https://www.getjust.ai/
- Type: Startups (AI role)
- Level: Senior
- Location: San Francisco, CA, US
- Work setup: On-site
- Pay: $130K to $250K base salary per year (USD)
- Posted: 2026-06-22
- Apply by: 2026-10-08
- Apply: https://www.ycombinator.com/companies/justai/jobs/ZfzMDXJ-senior-platform-engineer
- Page: https://www.1752.vc/careers/jobs/justai-senior-platform-engineer/

## About the role

You'll own the layer that sits between raw infrastructure and the product surface marketers touch: the campaign execution engine, the multi-tenant platform APIs, durable and stateful orchestration, and the SDKs and interfaces other teams (and our customers) build on. This is a high-leverage role, since the abstractions you design determine how fast everyone above you can move.

## What they're looking for

- 5+ years building large-scale distributed systems, with a track record of systems that sit between infrastructure and product (platform/API/SDK teams, execution engines, workflow orchestration, internal platforms)
- Deep experience with stateful, concurrent systems, with a strong grasp of consistency, idempotency, and failure modes
- You think in abstractions and contracts, and you've built interfaces other engineers depend on
- Comfort operating across the stack, from low-level systems concerns up to the developer experience of the people consuming your platform
- We care more about how you think about systems than which specific tools you've used

Tags: Engineering