In March, your senior engineer spent a week figuring out how to build your search system. She ruled out the obvious queuing approach — too slow, too expensive at scale — and picked something better. She wrote it all down. She left in October. Last month, a new engineer started rebuilding the same system using the exact approach she ruled out. Six months of work, repeating a solved mistake. AethrionX would have shown him her research the moment he opened the ticket.