1Planner-Executor & Multi-Agent TopologiesPlanner-executor systems split thinking from doing, while multi-agent topologies add roles, checks, and coordination costs.Advanced 2Orchestration, State & Control FlowHow software decides what happens next, remembers what matters, and keeps complex work from becoming accidental chaos.Advanced 3Tool Routing & GuardrailsHow AI systems choose tools, limit risk, and turn policy into dependable runtime behavior.Advanced 4Failure Recovery & DeterminismReliable systems do not avoid all failure; they make failure visible, bounded, recoverable, and as repeatable as the work allows.Advanced 5Evaluating Agent SystemsA practical guide to judging whether an agent system is useful, safe, reliable, and worth operating in the real world.Advanced