Your Coding Teacher

Some properties of distibuted systems: - Reliability: the system can tolerate faults (software or hardware) - Scalability: the system has good performance when load increases - Maintainability: the system is easy to extend and to operate

Some questions to consider to clarify requirements: - Read/write heavy sistem? (or both) - Expected # Users (average and peak) - Traffic patterns - Amount of data to store (for how long) - SLA - Consistency model? - Cost of development vs operations/maintenance

Perl was developed by Larry Wald in 1987 as a scripting language for text editing It is commonly used in: - Linux system administration - Web development - Network programming print "Hello, World!\n";

I've also wasted long hours debugging issues that came from: - Reading the wrong configuration file - Using outdated information from an internal wiki page - Problems with someone else's code - Copy-paste related errors When things go wrong, check your assumptions.

Bit-level operations on an integer x x |= 1<<7 -> set bit 7 (the first bit starts at index 0) x &= ~(1<<7) -> clear bit 7 x ^= 1<<7 -> toggle bit 7 mask = ((1<<8)-1) -> create an 8 bit mask (x >> 16) & 0xf -> extract bits 16 through 8 (x >> 7) & 1 -> test bit 7

We live in a world governed by distributed systems. From small intranets, to share printers, to the Internet

4 JavaScript interview questions What is a Callback function? What are Arrow functions? What is the usage of Function.prototype.bind? How to check if a value is null?

Make something fool-proof and someone will make a better fool

Instead of trying to figure out what's the next incremental improvements for a slow algorithm, sometimes it's better to try a complete different approach

"The language in which we express our ideas has a strong influence on our thought processes." - Donald Knuth

The best thing about a boolean is even if you are wrong, you are only off by a bit

"There are no significant bugs in our released software that any significant number of users want fixed." - Bill Gates

The best developers follow a simple principle "Always Be Learning"

In GCP, you can use preemptible virtual machines to save up to 80% of your costs. They are ideal for fault-tolerant, non-critical applications. You can save the progress of your job in a persistent disk using a shut-down script to continue where you left off.

Message queues in a tweet - Allows for asych processing - Stores messages that servers will read and process - Adds reliability (no message is lost) - Dead-letter queue: receives messages that couldn't be routed to their destination - Ex: SQS, Kafka, Rabbit MQ, Pub/Sub

Python's list comprehensions provides a concise way of creating a list from another. For example: cubes = [x**3 for x in a]. In general, they are clearer than maps and filters built-in function.

"Debugging is like being the detective in a crime movie where you are also the murderer." - Filipe Fortes

//TODO comments end up being //Never do's

In C++, to prevent resource leaks, use RAII Resource Acquisition Is Initialization Acquire resources in constructors and release them in destructors

The first 90% of a project takes 90% of development time. The last 10% takes the other 90% of the time.