Every software developer needs to know how the HTTP protocol works.

Here are the 8 fundamental things you need to grasp: ↓ 1. What is HTTP

HTTP is an application-level protocol based on a request-response paradigm.

Its primary use is encoding and transporting information between a client and a server.

A typical HTTP transaction is made of 2 steps:

• a client sends a request message to a server

• the server replies with a response message

As a senior software engineer, you should read these famous white papers from big tech companies (AWS, Google, Meta,..): ↓ 1. Dynamo: Amazon’s Highly Available Key-value Store

cs.cornell.edu/courses/cs5414…

2. Spanner: Google’s Globally-Distributed Database

static.googleusercontent.com/media/research…

3. Scaling Memcache at Facebook

usenix.org/system/files/c…

If you're a software engineer who wants to learn the core concepts about system design and distributed systems, read these 12 articles: ↓ 1. How RAFT solves the consensus problem in distributed systems: a step-by-step breakdown that every engineer can understand.

newsletter.francofernando.com/p/the-raft-con…

What is API pagination?

A lot of times, REST APIs need to return 100+ results.

API pagination is a way to break such data into chunks that are easy to work with.

This improves user experience and reduces server load.

These are the 3 kind of API pagination you need to know: ↓ 1. Offset-Based

The API uses two parameters: "offset" determines the position in the dataset, while "limit" specifies the maximum number of data to include on each page.

This approach became popular with apps using SQL, which already have LIMIT and OFFSET as part of the syntax.

Example: GET products?limit=20&offset40

Pros: It's simple to set up and lets you go straight to any page.

Cons: There are performance issues with large OFFSET values. It can cause data to be duplicated or skipped in dynamic datasets.

If you are a software engineer serious about getting better at algorithms and data structures, read these 12 articles: ↓ 1. How to use the two-pointer method to efficiently solving array and string problems (with code templates).

newsletter.francofernando.com/p/mastering-th…

Most developers think graphs are not important for their daily work.

But the reason is that they don't know graph algorithms and their use cases.

You will change your mind once you know these 5 algorithms: ↓ 1. Breadth-first search

It's a traversal algorithm implemented using a queue data structure.

It starts from a node and first explores all its adjacent nodes.

Then, it explores all nodes two steps away from the starting one, and so on.

Applications of BFS are:

● build web page indexes in web crawlers

● discover neighbor nodes in p2p networks

● find neighboring places in GPS navigation systems

If you're a backend engineer who want to get better at system design, read these 13 articles: ↓ 1. Common mistakes software engineers make during system design interviews and how to avoid them.

newsletter.francofernando.com/p/how-not-to-f…

9 LeetCode articles that will help you get ready for your next coding interview: ↓ 1.Two Pointers Patterns:

leetcode.com/discuss/study-…

2. Binary Search Patterns:

leetcode.com/discuss/study-…

3. Dynamic Programming Patterns: leetcode.com/discuss/study-…

If you are a senior software engineer who wants to improve his/her skills, read these 10 curated articles: ↓ 1. How to boost your career as a software engineer by communicating better with your peers, manager, and partners.

newsletter.francofernando.com/p/communication

Coming up with an algorithm to solve a problem is hard.

Without a proper approach, it's easy to get lost.

Here are 6 methods you can use to solve 99% of the problems: ↓ 1. Brute Force

It's the most basic approach.

• Methodically list all the possible candidates for the solution.

• Check to see if the problem statement is satisfied for each option.

• It always finds the best solution but doesn't scale with the input size.

Example: Find the closest pair of points

If you're a software engineer who want to get better at tech interviews, read these 10 articles: ↓ 1. Common mistakes software engineers make during system design interviews and how to avoid them.

newsletter.francofernando.com/p/how-not-to-f…

What's the difference between load balancers, reverse proxies, and API Gateways? ↓ 1. Load Balancers

Their main job is sending client requests to several servers. The goal is to spread the load evenly so there are no bottlenecks and the system works smoothly.

They work in this way:

- The load balancer gets requests from clients

- The load balancer selects a server based on a predefined algorithm

- The request is sent to the service that was chosen

- The server processes the request and returns the response to the load balancer

- The load balancer then forwards the response back to the client

The main benefit of using a load balancer is that it increases throughput, reduces response time, and optimizes resource utilization.

If you're a software engineer who want to get better at system design, read these 10 articles: ↓ 1. How Shopify uses sandboxing to build secure checkout pages

newsletter.francofernando.com/p/the-shopify-…

What are message queues?

They are a way to let two services talk asynchronously and are critical in any distributed system.

A producer creates messages and puts them in the queue.

A consumer gets messages from the queue and processes them.

Here's a practical use case: ↓ Multimedia applications often need to process content to meet different users' needs.

Simply sending the request to a processing service wouldn't be a great idea because the service may not work for any reason.

A better approach is to send the request to a message queue and put the content in a file store. The queue works as a temporary buffer until the service can process the request.

Latency and throughput are critical for any application.

But many developers get them wrong or use them in the wrong way.

Here are the key differences you should know: ↓ Latency is a way to measure how long an operation takes to finish.

You can think of it as the time it takes for your system to respond.

For example, latency is the time from clicking the link to when the data displays on your screen.

In computer networking, the most common latency is round-trip delay. That's the time it takes for a client request to reach the server and for the response to return.

Network latency is usually measured in milliseconds (ms) using ping tests or traceroute.

In any coding interview, you must solve problems about arrays or strings.

I completed over 350+ of them and learned to avoid the usual mistakes.

Here are some tips that will help you improve: ↓ 1. You can efficiently access both ends of an array and use the 2-pointer technique.

2. It's usually possible optimize to O(1) space a brute force solution taking O(N) space.

3. Consider the possibility of overwriting an element instead of removing it.

Solving 300+ LeetCode problems doesn't mean you'll pass your coding interview.

What holds you back are not your coding skills but the way you approach problems.

If you want to do better, use this practical 7-step strategy: ↓ Step 1: Listen

Pay close attention to the problem description and catch every detail.

Each piece of information is crucial in finding the optimal solution.

For example, if the interviewer gives you sorted input data, this likely affects the optimal solution.

Many software engineers have trouble with recursion during coding interviews.

If you want to become good at solving such problems, learn these 6 templates: ↓ 1. Iteration

Any problem that can be solved with loops can also be solved using recursion.

Sometimes recursion provides a more concise and elegant solution, even if less efficient.

Example:

- traversing a linked list in reverse order

The sliding window method isn't just a trick for coding interviews.

It's the cheat code for cracking most array and string problems.

Here's how you can quickly grasp and use it: [1/7] ↓ A sliding window is a subarray that moves from left to right through an array.

The window is defined by two pointers representing its left and right bound.

The window size can be fixed or variable.

[2/7]

Most developers don't use trees in their daily work.

But the reason is that they're avoiding tree problems.

You won't need to do that anymore once you know these 4 data structures: ↓ 1. Binary Search Trees (BST)

It's a constrained extension of a binary tree with a unique property.

Given a node, the value of its left child is less than or equal to the parent value.

The value of the right child is greater than or equal to the parent's value

The primary use cases of BSTs are:

- implement simple sorting algorithms
- maintain a sorted stream of data
- implement double-ended priority queues

The most popular BST implementations are balanced trees like Red Black or AVL.

Availability is critical for distributed systems.

A downtime of 1 hour:

• costs from $1K to $1M.
• affect the system credibility
• decrease the customers trust

Here's how you can get a system available: (cont'd) ↓ 1. Definition

Availability is a measure of how a system is resistant to failures.

The more a system stays operational when a component fails, the higher its availability.