5 essential System Design security practices for 2025
Imagine this: You build a fortress with walls tall enough to touch clouds ... but forget to lock the door.
That's what happened to Equifax in 2017, when a single unpatched vulnerability in Apache Struts exposed the personal data of 140+ million people.
The consequences were catastrophic: an estimated loss of $1.4 billion, plus a long string of lawsuits and regulatory penalties.
The kicker here is that the breach didn't happen because Equifax lacked a strong security system. It happened because of one tiny oversight.
Equifax's story is a stark reminder of the absolute importance of security in System Design. One missed update, one weak API, or one poorly planned component can make even the strongest systems come crashing down.
In today's newsletter, we'll cover:
How cybersecurity threats are becoming more sophisticated
The role of security controls in protecting your system
5 essential security measures to strengthen your System Design
8 key techniques for bolstering security
Let's go.
The evolution of cybersecurity threats
Security threats have evolved considerably—becoming smarter, faster, and more adaptive. In the early days, cyber threats were simpler, like viruses spread through floppy disks or phishing emails that were easy to spot.
But as technology advanced, so did attackers' methods. Today, threats are highly sophisticated as bad agents use AI to predict weakness, social engineering to manipulate users, and complex malware to slip through the cracks. We now deal with ransomware, supply chain vulnerabilities, and advanced, persistent threats.
Here's a closer look at how threats have evolved over time:
Timeline of evolving threats
Timeframe | Threat Type | Common Tactics | Defense focus |
The early 1990s | Basic viruses and worms | Spreading via floppy disks, email | Antivirus software, manual updates |
Late 1990s–Early 2000s | Phishing and malware | Fake emails/websites, malware files | Firewalls, email filtering, user awareness |
Mid 2000s | Spyware and adware | Secretly installed software | Spyware removal tools, strict app permissions |
2010–2015 | Advanced persistent threats (APT) | Targeted, long-term attacks | Intrusion detection, encryption, incident response |
2015–2020 | Ransomware and crypto-jacking | Encrypting data, mining cryptocurrency | Backup strategies, ransomware protection, threat intelligence |
2020–Present | AI-powered and supply chain attacks | AI predicting weaknesses, attacking vendors | AI-driven security, supply chain risk management, zero trust architecture |
Security is no longer just about keeping viruses out—it's a constant game of chess, where every move by attackers demands an equally smart countermove.
Importance of security-first System Design
Security is a fundamental part of System Design, not a last-minute addition.
Instead of responding to threats, organizations must proactively design systems that anticipate them effectively. The cost of poor security architecture goes beyond financial loss—it can permanently damage a business’s reputation.
A good example of that is Yahoo's 2013 data breach, where attackers stole the personal information of all 3 billion user accounts. Yahoo's delayed response and lack of security controls led to an irrevocable loss of trust, reducing its sale value by $340 million.
Smart security starts with early risk assessments—evaluating every component for vulnerabilities. Skipping this step can lead to weaknesses that bring your system down. It's also important for:
Proactive defense against cyber threats and vulnerabilities.
Adhering to data privacy and compliance such as
GDPR General Data Protection Regulation (GDPR) is a European Union regulation that governs data privacy and protection of individuals within the EU and the European Economic Area (EEA). HIPAA Health Insurance Portability and Accountability Act (HIPAA) is a US law that regulates the handling of sensitive health information (PHI) to protect patient privacy. CCPA California Consumer Privacy Act (CCPA) is a U.S. law granting California residents rights regarding collecting, using, and selling personal data. Preventing financial loss or cost efficiency.
Securing the company’s reputation and future.
Next, we’ll explore the security controls that make this proactive approach a reality.
The importance of security controls
Understanding the importance of security is one thing. Turning that awareness into action is another.
This is where security controls come in—they’re the concrete measures that bridge the gap between security concepts and real-world protection. Security controls enforce policies and mitigate risks, forming the backbone of a secure system.
The 3 categories of security controls include:
Preventive controls: These are designed to stop threats before they occur. They serve as the first line of defense, aiming to prevent unauthorized access and mitigate vulnerabilities, including techniques like authentication, authorization, encryption, firewalls, and antivirus or antimalware.
Detective controls: They identify and alert the administrator or cyber security team of potential issues, such as intrusion detection, allowing for swift action. These include logging, auditing, monitoring, alerting, and intrusion detection systems.
Corrective controls: They aim to mitigate damage after a security incident. These controls focus on recovery and ensuring the system can return to a secure state, including backup and recovery, quarantine isolation, and patch management.
These security controls should be applied at various system levels, such as the network, host, application, data, and user.
5 essential security measures in System Design
Now we're ready to dive into the core components that will help safeguard your systems.
Building a secure system requires integrating components that strengthen security at every layer. Here’s a look at the 5 key elements of System Design and their roles in protection:
