Backend Engineer, Rust

Build systems people can trust with the things they cannot replace. Cosmic Rocks is building Merka Vault, a home for people’s digital lives that puts control in their hands. We’re looking for a backend engineer who enjoys Rust, thinks carefully about failure, and wants to turn complex infrastructure into a dependable everyday product. What you’ll work on • Build Rust services and APIs behind the product. • Develop reliable data flows across devices, storage, and backups. • Make interrupted operations, retries, and recovery behave predictably. • Improve performance, observability, and automated testing. • Work directly with the founder and frontend engineer to make sound technical choices that serve the user. You’ll be a strong fit if you • Have practical experience building software in Rust. • Understand async programming, concurrency, networking, and persistent storage. • Can reason about partial failures and explain the tradeoffs in your design. • Care about maintainable code, useful documentation, and security boundaries. • Take initiative and know when to bring others into a decision. Experience with distributed systems, synchronization, encrypted storage, or backup and restore would be especially relevant. Why this role matters A successful restore is more than a passing test. It can mean someone gets years of family photos back. You’ll help build the behavior that makes that trust deserved. Interested? Send a short introduction and something you built. Tell us about a difficult failure you diagnosed, what caused it, and what you changed.