2026 is the year AI agents move from demos to production, but most multi-agent systems still fail in the wild. This talk dives deep into the architectural patterns, orchestration frameworks, and engineering principles behind reliable agentic systems. We'll explore tool use, memory, planning loops, and inter-agent communication, alongside the often-overlooked challenges of observability, cost control, and failure recovery. Expect real-world case studies, anti-patterns to avoid, and a practical blueprint for building agents that ship.