Edge Investigation Map

Problem	Start here	Continue when needed
Unexpected fill price	Orders → Decision	Ticks for quote context
Reject	Orders → Decision	Alarm/System log for system signals
Delay	Orders → Decision	Execution for counterparty latency
Partial fill	Orders → Order	Execution for multiple fills
Counterparty timeout	Orders → Execution	Alarm log / System summary
Missing order	Orders → Order	Decision Stream / Logs
Stale quote	Dashboard	Ticks / Connection Status / Alarm log
Wide spread	Ticks	Dashboard / Alarm log
Many clients affected	Orders by symbol/time	System summary / alarms

Use stable IDs, align Server Time and expand scope only with evidence.