This part should: https://github.com/DeviceFarmer/adbkit-apkreader/blob/bd84b34adc6cddaf477fe6c5d8df1539682e9f0c/lib/apkreader.js#L35 be in async so the main thread doesn't get stuck for really large files. Not adding more details because I think it's pretty straight forward. If you need more details let me know.