About the role
Postscript is the AI messaging platform trusted by 20,000+ Shopify brands — including Brooklinen, Ruggable, True Classic, and Dr. Squatch.
With a mission to make SMS your number one revenue driving channel, we built the best-in-class SMS marketing platform and launched revenue-driving AI features not available on any other platform. And we're just getting started.
Backed by Greylock and Y Combinator, fully remote since 2018.
Job Description
Staff Platform Engineer (Infrastructure)
We are seeking an experienced Staff Platform Engineer to help build and operate Acorn, Postscript's next-generation CDP and messaging platform: ~52 Rust/Python services on EKS, built to run at 500K+ events/sec for 20K+ merchants.
What makes this role different: the platform is agent-operated. Deploys, migrations, drift reconciliation, and infra standup are automated and encoded as self-verifying runbooks that AI agents execute. We are not hiring someone to run those procedures by hand. We are hiring the person who designs the system, writes the guardrails that let agents execute it safely, and owns the failures no runbook covers yet.
Primary duties
- System & Platform Design: Own infra topology, scaling and blast-radius boundaries, the build/deploy graph, database ownership boundaries, and cost ceilings — the decisions agents execute but can't make.
- Guardrail Engineering: Build the validation gates, idempotency checks, drift detectors, and runbooks that keep both humans and agents from doing damage. Your deliverable is the safety system, not the deploy.
- Escalation Tier: Diagnose the novel failures — consumer lag, DLQs, materialized-view chains, consent ordering. Write the runbook the first time; agents handle it after.
