I'm GCL- and Market-grinding a 2-Source + Oxygen room, on ~4 cpu (averaged over every 3k ticks) on my original grown-from-Tutorial codebase. I've since halted improvement of that while I work on a new generation of code which is multi-room and remote-mining aware, but with how busy I've been with my daughter having arrived this month, I don't expect to have that codebase ready for live use until Summer.

Number one: when I first installed the server, I would get this error repeatedly in the server GUI. Restarting Steam fixed it, but it's a bit confusing why that should be so. A better error message than "initAPI() failure" would probably be sufficient.

Loading mods from "D:\SteamLibrary\steamapps\common\Screeps\server\mods\mods.json"
Connecting to storage
Starting CLI server
STEAM_KEY environment variable is not found, trying to connect to local Steam client
Error: greenworks.initAPI() failure
 at Object.startServer (D:\SteamLibrary\steamapps\common\Screeps\server\modules\backend\lib\game\server.js:95:19)
 at common.storage._connect.then.then (D:\SteamLibrary\steamapps\common\Screeps\server\modules\backend\lib\index.js:16:28)
 at _fulfilled (D:\SteamLibrary\steamapps\common\Screeps\server\modules\common\node_modules\q\q.js:834:54)
 at self.promiseDispatch.done (D:\SteamLibrary\steamapps\common\Screeps\server\modules\common\node_modules\q\q.js:863:30)
 at Promise.promise.promiseDispatch (D:\SteamLibrary\steamapps\common\Screeps\server\modules\common\node_modules\q\q.js:796:13)
 at D:\SteamLibrary\steamapps\common\Screeps\server\modules\common\node_modules\q\q.js:604:44
 at runSingle (D:\SteamLibrary\steamapps\common\Screeps\server\modules\common\node_modules\q\q.js:137:13)
 at flush (D:\SteamLibrary\steamapps\common\Screeps\server\modules\common\node_modules\q\q.js:125:13)
 at _combinedTickCallback (internal/process/next_tick.js:67:7)
 at process._tickCallback (internal/process/next_tick.js:98:9)

Number two: periodically, I see these errors. Best guess: sometimes the loader doesn't load the entire source file before trying to execute it.

[7:32:29 PM]Script execution has been terminated: Unknown system error
[7:32:29 PM]Script execution has been terminated: Unknown system error
[7:33:04 PM]SyntaxError: Unexpected token )
 at Object.module.exports.loop (main:120:9)
 at __mainLoop:1:52
 at ContextifyScript.Script.runInContext (vm.js:35:29)