Role Summary: We’re hiring a Staff Engineer – Backend (Data Systems) to own and evolve the data backbone that powers messaging at scale inside HighLevel’s Conversations platform. You’ll design, operate, and scale systems that handle billions of documents across MongoDB, Firestore, Redis, and ElasticSearch — with reliability, predictability, and engineering clarity as non-negotiables. This is a hands-on IC role — you’ll code, design, review, and guide. You’ll set the standard for how we think about databases, APIs, and engineering craft. The goal: make our data systems boring in the best possible way — predictable, fast, and easy to trust. Your first project will be to re-architect and scale ElasticSearch to handle billions of documents efficiently while setting best practices for schema design, observability, and testing discipline across the org.