Job Description
About the Role We are seeking a Senior Backend & Infra Engineer to help shape the core infrastructure powering Pika's products. In this role, you will operate at the intersection of systems engineering and advanced AI, taking ownership of the unified architecture that supports our platform—from real-time messaging and scalable APIs to cognitive agent runtimes and orchestration frameworks. You will architect and build robust, distributed backend systems enabling autonomous AI agents to reason, use tools, recall memories, and act across multiple platforms at scale. This high-ownership position means your architectural decisions will directly impact how millions of users experience generative AI. As a senior engineer, you’ll also play a key role in raising the technical bar through guidance, RFCs, code reviews, and mentorship. What You'll Do Architect Distributed Systems: Build scalable backend, infrastructure, and agentic services for Pika’s web, mobile, and multi-platform products. Evolve the Agent Runtime: Design and optimize the core execution loop that handles agent reasoning, tool-use frameworks, function calling, memory retrieval, and multi-step orchestration. Design Real-Time Architecture: Own and scale real-time messaging infrastructure, event-driven architectures, WebSocket connections, and pub/sub patterns for throughput, latency, and reliability. Implement Core AI Capabilities: Optimize LLM integrations, multi-provider model routing (Claude, GPT, Gemini, open-source), context window management, cost optimization, and streaming responses. Build Memory & Retrieval Systems: Design semantic search and vector-based embedding infrastructure to handle long-term memory, working memory, and episodic recall for autonomous agents. Own Backend Logic End-to-End: Drive database modeling (SQL/NoSQL), API design, performance tuning, and production reliability for high-traffic pipelines. Drive Technical Excellence: Write RFCs, evaluate complex technical trade-offs, mentor j
