I'd be shocked if CSX had only 137 people in IT.
By comparison, my airline has over 2,000 not including the contractors.
We also use TCS to handle what's referred to as core support. That's the developers who monitor systems to make sure they're running, review logs for errors, and test/deploy new changes. They handle tasks that require the least amount of intuition or knowledge to perform. They follow instructions from a runbook.
What TCS doesn't do for us is anything requiring decisions or judgment calls. Tasks such as designing code or our architecture, security design or maintaining our networks are still inhouse and likely will remain that way. That's not something you want to lose visibility or accountability over.
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Owner/operator of
TrainSim.com (the internet's largest train simulation community)