River

River is a Bitcoin-only financial institution building a consumer financial app to save in bitcoin and spend in dollars. The company custodizes over 25,000 BTC, serves individuals and businesses across the U.S., is profitable, and publishes cryptographic proof of reserves monthly and company financials annually. Engineering work includes real-time Bitcoin and USD payments, trading, and settlement on an Elixir monolith with a unified GraphQL API; next-generation Bitcoin custody with quorum signing, key ceremonies, and geo-redundant infrastructure; scaling ML/AI systems (Python, PyTorch, XGBoost, LLMs) to automate operations and combat fraud/risk; a ground-up React and React Native rewrite of the consumer app; and porting Lightning Network infrastructure from Go into Elixir. Hiring Senior and Staff engineers for Elixir, React, and ML/AI roles. Founder and CEO (Alex) is actively involved in shipping code.