@rkenmi - Search Results

Virtual Memory

... for your running applications. Memory is structured and managed in two different ways; paging and segmentation. Segmentation Segmentation allocates memory for each application into physical memory based on their size.

September 27, 2020

CSR vs. SSR

Introduction 10 years ago, Amazon found that every 100ms of latency cost them 1% in sales. Google found an extra .5 seconds in search page generation time dropped traffic by 20%. A broker could lose $4 million in revenues per millisecond if their electronic trading platform is 5 milliseconds behind the competition.

June 21, 2020

B-Trees vs. LSM Trees

B-Trees Modern databases are typically represented as B-Trees or LSM Trees (Log structured merge trees). B-trees are "tried and true" data structures that are popular in database usage, most notably SQL databases.

March 14, 2018

RDBMS Indexing

Introduction As illustrated in this article, indexing is one of the easiest and most effective tweaks you can add to your SQL database. However, indexing might seem like magic, and you might also not be too sure which field to index in the first place.

January 24, 2021

Javascript Essentials

Hoisting Hoisting is JavaScript's default behavior of moving declarations to the top. Given the following Javascript code, what is the expected output, and why? fcn2(); fcn1(); function fcn2(){ alert("hi"); } var fcn1 = function(){ alert("hey") } The expected output is a pop up alert that says "hi", followed by an error that fcn1 isn't defined.

November 12, 2017

Web Development 101

HTTP vs. HTTPS HTTP stands for Hypertext Transfer Protocol. It typically runs on TCP port 80. It is a protocol for sending data through browsers in the form of webpages and such. One major flaw with HTTP is that it is vulnerable to man in the middle attacks.

November 9, 2017

HTML and CSS Concepts

HTML Hypertext Markup Language is the standard markup language for creating web pages and web applications. It was created by Tim Berners and it represents a document in the world wide web. DOM The DOM is an interface that treats a HTML document as a tree structure wherein each node is an object representing a part of the element.

March 22, 2019

Bloom Filter

A set data structure uses a hashing function to store values and to verify if a value exists. Bloom filters are similar in that it uses multiple hashing functions to store values and to verify if a value exists.

October 14, 2019

Working with Production at Amazon Retail Website

A short background Prior to working at Amazon, I was developing software at a couple of startups, mostly working with products that were in the conceptual phase or the development phase. One of the things I desired the most was to have exposure to products that were live in production or to bring a development project to production.

December 28, 2021

Seattle Conference on Scalability: YouTube Scalability

Notes Apache isn't that great at serving static content for a large number of requests vs. NetScaler load balancing Python is fast enough There are many other bottlenecks such as waiting for calls from DB, cache, etc.

December 25, 2020

Overlapping linked lists

Given two linked list nodes, one might overlap the other. That is, one linked list might contain a sequence that is already in the other linked list. The two linked lists share a common node. Problem Build a function that takes two singly linked lists and returns a boolean output that signifies whether or not the two linked lists share a common node.

September 26, 2017

Arcade fun with Python and pygame

Source: https://github.com/rkenmi/R-Typo I recently configured one of my pet projects to work with pyinstaller, which happens to be a nifty tool for creating one-file executables with multi-platform support.

August 24, 2017

DNS

DNS (Domain name system) is essentially a phonebook for internet addresses on the Internet. Every URL with alphanumeric characters are mapped to IP addresses, either IPv4 or IPv6. That means https://google.

March 5, 2021

Algorithm Interview Problems

Welcome This page contains solutions to common interview problems that may be encountered. Arrays Longest Substring Without Repeating Characters Rotate a 2D Matrix Buy/Sell Two Stocks Merge Intervals Next Permutation Random Permutation Replace all occurrences of a space with a string Linked Lists Reversing sublists of singly linked lists Cycles in singly linked lists Overlapping singly linked lists Merging two sorted singly linked lists Merge k sorted lists Recursion Counting the path of sums Money Denominations Phone Number Mnemonics Unique Permutation Dynamic Programming Perfect Squares Find the Maximum Min Path Binary Trees Tree Symmetry Iterative In-Order Traversal of a Binary Tree Construct a Binary Tree from Pre-Order Traversal and In-Order Traversal BST Validate a BST Binary Heaps Merge k sorted lists Graphs Find a path in a maze from start to finish Flip colors in a matrix Search Search in a rotated sorted array Find the Duplicate Number Greedy Algorithms Queue Reconstruction By Height Trie Build a Trie in Python Invariant Compute the max.

January 25, 2019

Atomic operations with Elasticsearch

Preface Elasticsearch is a distributed, open source search and analytics engine for all types of data, including textual, numerical, geospatial, structured, and unstructured. Key Terms: Document - Serialized JSON data.

May 6, 2020

Data stores in Software Architectures

Use Cases There are many ways to store your data. In this article we'll walk through some examples of data storage in common system designs. Reminder: There is no single best storage choice and they may vary heavily depending on things such as access patterns and scale.

July 19, 2021