Design a Flight Aggregator Service

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RDS vs Aurora DB

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Optional Vs Null Check

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The purpose of Optional is not to replace every single null reference in your codebase but rather to help design better APIs in which—just by reading the signature of a method—users can tell whether to expect an optional value. In addition, Optional forces you to actively unwrap an Optional to deal with the absence of a value; as a result, you protect your code against unintended null pointer exceptions. String version = computer.getSoundcard().getUSB().getVersion(); This code can lead to NullPointerException. Handle NullPointerException - This code looks ugly. String version = "UNKNOWN"; if(computer != null){   Soundcard soundcard = computer.getSoundcard();   if(soundcard != null){     USB usb = soundcard.getUSB();     if(usb != null){       version = usb.getVersion();     }   } } String name = computer.flatMap(Computer::getSoundcard)                           .f...
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GIT Rebase vs Merge

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  How does Git Work? For understanding the working of git, we need to understand the two fundamental concepts in git which is git commit and git branch. Let’s understand these two terms respectively. What is a Commit? Commit is defined as the location where the code and its changes are stored.  In git merge, looking at the end diagram, one can make out Commit A and B came from the feature branch. However, in the git-rebase diagram, it is difficult to understand where commits A and B came from. Therefore, we do git merge when we want our team to understand logs in a way where they can identify where each commit is coming from. We use Git Rebase when the logs of the repository will not be referred by anyone else. To summarise, we can use Git Rebase, when we are working on branches, which cannot be seen by other developers. And we use Git Merge when the target and source branch can be viewed by other developers. How can Git Rebase and Git Merge be used together? Let us take an ex...
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