Hey Guys,

Really sorry for missing the emails last week!

Unfortunately I ended up catching COVID (right when vaccines are rolling out of course), and was pretty much knocked out for all of last week.

Feeling a lot better now, so we’re back to it!

Thank you for your patience!

Tech Snippets

• AWS’s This is My Architecture series is pretty fantastic. CTOs of various companies come and discuss how they’ve architected their systems.

  • My favorite video so far has been on Nordstrom’s Event-Sourced Serverless Architecture.

  • You can view the full playlist here.

  • The videos are by AWS, so they do shill their service a bit haha. But the concepts can be applied to any cloud provider!

• Amazing article on Software Engineering compensation in Europe.

  • Software Engineering compensation can be split into three groups

    • Companies only benchmarking against local competition - Non-tech companies that view engineering as a “cost center”.

    • Companies benchmarking against all local companies - Companies like Disney, Nike, Booking, etc. These companies pay better but still aren’t tech companies. They’re not competing for the best engineering talent.

    • Companies benchmarking on a regional/global scale - Big Tech companies like Facebook/Google are in this grouping. These companies invest the most in engineering talent.

  • COVID-19 has been great for European Software Engineering salaries as Big Tech companies have been shifting more roles to the EU. Stripe, Spotify and Coinbase are a couple examples of companies that are going much harder on European roles.

Interview Question

You are given the root of a binary tree.

We define the “difference” of nodes A and B as

difference = |A.val - B.val|

Find the largest difference between any two nodes A and B in the tree, as long as A is an ancestor of B.

Here’s the question in LeetCode.

We’ll send a detailed solution tomorrow, so make sure you move our emails to primary, so you don’t miss them!

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Previous Solution

As a refresher, here’s the last question

You are given the root of a Binary Search Tree and an integer k.

Return the kth smallest element in the BST.

Here’s the question in LeetCode.

Solution

We can solve this question with an iterative in-order (smallest to largest) traversal.

If you don’t know how to implement an iterative in-order traversal, check this out.

While we run our traversal, we use a counter variable to keep track of how many nodes we’ve processed.

Once we’re on the kth node, we return the value.

Here’s the Python 3 code.

Can you analyze the time complexity of our solution?

Reply back with your estimate!

We’ll tell you if you’re correct (or we’ll tell you the answer if you’re wrong).