Senior Backend Engineer

Role Description

We're seeking a Senior Backend Engineer to join our fast-paced team to design, develop, and implement new infrastructure for Littlebird, our personalized AI teammate for Mac and Android (Windows soon!). We’re building personal AI; a thought partner that connects dots in your work and helps you think.

We're an async-first team that values craft and ownership. Our engineers live at the intersection of genuine research curiosity and production discipline: you'll push the frontier in areas like realtime data, search, and inference, then wrestle those ideas into systems that are fast, lean, and built to scale.

You will architect the system that allows our agent to reason, remember, and evolve. You'll develop core infrastructure that turns messy, unstructured user data into a coherent world model.

Some of the hard problems you'll solve:

• Build AI Memory: Lead the charge to design and implement our next-generation memory system.
• Scale Our Data & Retrieval Pipelines: Ensure our data ingestion, hybrid search, and re-ranking pipelines are fast, reliable, and cost-effective.
• Security: Ensure our infrastructure is highly secure and observable, with a focus on speed and cost.
• Graph-based Retrieval: Efficiently query a graph to provide the agent with rich, structured context, moving beyond simple semantic search.

Qualifications

• Deep experience building and scaling data-intensive backend systems in Python or Go.
• Strong system-design skills and experience working with distributed systems.
• A clear mental model for data structures and their trade-offs.
• Hands-on experience with RAG pipelines.
• Production experience with modern cloud infrastructure, observability tooling, and PostgreSQL.
• A pragmatic approach to building solutions.

Benefits

• Remote-friendly work environment.
• Collaborative team culture.
• Opportunity to shape infrastructure decisions.
• Competitive compensation packages including stock and health benefits, paid time off, and parental leave.
• 401k options for all US-based employees.
• Flexible working hours across multiple time zones.