Up until the 787, Boeing was an engineering company who did the lion's share of it's own R&D and fabrication. For all intents and purposes they were effectively

Up until the 787, Boeing was an engineering company who did the lion's share of it's own R&D and fabrication. For all intents and purposes they were effectively the airline manufacturing industry to a lot of people. The 787 changed all that, Boeing moved their longtime headquarters to Chicago, outsourced all their manufacturing, to follow just in time manufacturing and offload risk to contractors. In more recent years Boeing has started to bring a lot of their manufacturing back in house. They're not totally vertically integrated like Tesla is attempting to do right now (they just opened a lithium ore processing plant) but they used to build most of their own sub assemblies.