Senior Software Engineer - Full Stack

ABOUT CINDER Cinder builds the infrastructure that keeps the world's most important digital platforms true to what they stand for. When a platform needs to write moderation policies, route content to reviewers, run AI agents against abuse, file NCMEC reports, or measure how their safety programs are performing, they use Cinder. Our customers are some of the largest internet platforms in the world. The decisions made in our software directly determine what stays up, what comes down, and how users are treated. We're a small engineering team. You'll ship features that go live to enterprise customers within days, not quarters, and you'll hear directly from the people using what you built. WHY THIS ROLE You'd be building the infrastructure that some of the largest online communities in the world depend on to function. The problems aren't hypothetical: state-sponsored disinformation, CSAM reporting, coordinated abuse at scale. The software you build is used daily by the reviewers, investigators, and T&S leads making the calls that define what a platform stands for. This is an early-stage company with a mature product and real enterprise customers. You'll have outsized influence on architecture, product direction, and engineering culture. WHAT YOU'D ACTUALLY WORK ON This isn't a generic full-stack role. Here's what's actually on the roadmap right now and what you'd be contributing to: - AI agents that review content against customer policies, callable from within our durable workflow engine. We're moving from hardcoded LLM prompts to a configurable agent spec that customers can edit and deploy themselves. - A workflow engine built on Restate for durable execution. Engineers build new nodes that customers wire together to automate moderation pipelines, NCMEC reporting, enforcement actions, and more. - Review queue tooling: the core UI where moderators and investigators spend their day. You'd work on features like QA decision overrides, attribute-level labeling, forms, and s