Senior Backend Engineer at cash-flow seed-stage fintech marketplace

Senior Backend Engineer

Not Disclosed

Cash-flow positive seed-stage fintech startup building a modern trading marketplace for private market stock

San Francisco, USA

Join a high-velocity engineering team redefining private market investing for institutional clients. You will design and own core backend systems, building scalable services that transform fragmented data into institutional-grade insights. This is a pivotal role for an engineer who thrives on speed and wants to ship AI-native workflows that power billions in order volume.

• Work on a platform that has already achieved cash-flow positivity and manages billions of dollars in live order volume for the world’s leading institutional investors.
• Play a foundational role in an elite, fast-moving engineering team where you will directly influence architecture and build AI-native products like MCP servers for LLM interactions.
• Experience the best of both worlds: the high growth and impact of a seed‑stage startup combined with the stability of a proven, trusted market reputation.

• Design, build, and scale core backend systems and APIs that power a modern marketplace for private company stock and research.
• Develop automated data pipelines using LLMs to ingest, structure, and enrich complex financial data from fragmented sources into high-quality datasets.
• Architect and maintain modular, event-driven services and MCP servers that enable clients to interact with platform data directly through AI agents.

• 4+ years of backend or full-stack experience, with a strong background in Type Script or typed functional languages like Scala, Rust, or Haskell.
• Proven track record in a high-velocity, early-stage startup environment, demonstrating the ability to ship production systems quickly using modern AI development tools.
• Located in the San Francisco Bay Area and excited to collaborate in-person at least 3 days per week in a high-ownership, low-ego engineering culture.