Welcome to the team! As a new backend engineer, your first few weeks will be focused on getting oriented with our codebase, tools, and team processes. We recommend beginning with a review of our system architecture documentation, which will give you a high-level understanding of how our services interact before you dive into any specific area.

Once you have a grasp of the overall architecture, you should set up your local development environment. Your team lead will share the relevant repository links and environment variables needed to get the stack running. Don't hesitate to ask for help — the setup process can be tricky the first time.

In your first week, try to get your first pull request merged, even if it's a small improvement or documentation fix. This helps you go through the full development cycle — branching, writing code, running tests, and getting a code review — in a low-stakes context.

During weeks two and three, you'll be gradually assigned more complex tasks as you become comfortable with the codebase. We hold sprint planning on Mondays and a team retrospective every two weeks. You'll also be assigned a buddy engineer who can answer questions during your first month.

The TCP/IP model is a conceptual framework that describes how data is transmitted over a network. It consists of four layers, each responsible for a specific aspect of communication. Understanding these layers is essential for networking exams as questions frequently test your ability to map protocols to their respective layers.

The Application Layer is the topmost layer and is where user-facing protocols operate. This includes HTTP, HTTPS, FTP, SMTP, and DNS. When you browse a website, your browser interacts at this layer.

Below that is the Transport Layer, which handles end-to-end communication between processes. The two main protocols here are TCP, which provides reliable, ordered, and error-checked delivery, and UDP, which sacrifices reliability for speed and is used in applications like video streaming or gaming.

The Internet Layer (sometimes called the Network Layer) is responsible for logical addressing and routing. IP operates here, assigning source and destination addresses to packets and determining the best path through the network. ICMP also operates at this layer.

Finally, the Network Access Layer (also called the Link Layer) handles the physical transmission of data on the local network. Ethernet and Wi-Fi protocols operate here, dealing with MAC addresses and frame formatting.

Compound interest is often called the eighth wonder of the world, and for good reason. Unlike simple interest, which grows linearly, compound interest grows exponentially — meaning the rate of growth itself increases over time as you earn returns on your returns.

The mental model to internalize is this: every unit of money you invest today is not just one unit — it is the seed of a tree whose branching grows faster and faster. In year one, a branch grows. In year two, every branch grows new branches. By year thirty, the tree is enormous compared to what a simple interest model would produce.

The key variables are rate, time, and frequency of compounding. Of these, time is the most powerful and the most overlooked. An investor who starts at 25 will significantly outperform one who starts at 35, even if the late starter saves more money per year, purely because of the extra decade of compounding.

The practical implication is that delay is the enemy. Every year you wait is not just one year of returns lost — it is one year of exponential branching removed from your future. This is why financial advisors emphasize starting early above all other advice.