I once advised a promising fintech startup that stored their AWS keys in a private GitHub repository. An engineer, working late on a feature, accidentally made the repository public for just a few minutes. That was enough. Within hours, crypto-miners had spun up dozens of high-end servers using their credentials, racking up a five-figure bill before anyone even noticed. That’s how fast it can happen.
Starting a company is exciting. There’s energy, ideas flying around, fast decisions, and late nights. But in all that rush, security often gets pushed to the side. Many startups don’t take it seriously until it’s too late. And the damage is done.
Security isn’t just for big companies. In fact, startups are often easier targets because they move fast and assume they’re too small to matter. That’s a dangerous mindset. According to IBM’s 2024 Cost of a Data Breach Report, the average cost of a breach has surged to $4.88 million, a clear signal that even small vulnerabilities can lead to devastating financial and reputational costs. Truly, startups can’t afford to ignore software security, and the “we’ll fix it later” mindset is a recipe for disaster.
One of the biggest mistakes is not thinking about security from day one. It’s easy to put it off. But the earlier you start building secure habits, the easier it is to scale them. Waiting means you’ll have to go back and fix things that were built wrong, which slows you down and sometimes isn’t even possible without a full rebuild.
Another common problem is weak or reused passwords. You’d think we’d all know better by now, but in startups where things are moving fast, it still happens all the time. Developers use default passwords. Team members share logins. Someone stores passwords in a Google doc. It only takes one exposed password to let someone in. Using strong, unique passwords — and better yet, password managers — is a simple step that goes a long way. Adding two-factor authentication is another easy win.
A lot of startups also forget to secure their code repositories. Platforms like GitHub are great, but if access isn’t limited or monitored, anyone can stumble across code, API keys, or sensitive data. Sometimes people even accidentally push credentials or private information into public repos. It’s important to check what you’re uploading and to use .gitignore files properly. Scan repos for secrets before pushing anything, and restrict access to those who really need it.
Another area where mistakes happen is in third-party services. Every new tool is a new potential entry point for attackers. If you’re not reviewing what data each service has access to, or if you’re just copying and pasting API keys without thinking, you’re opening yourself up to risk. Only use trusted services, give them the minimum access needed, and always keep track of what’s connected to your system.
Lack of updates is another common issue. When you’re trying to build fast, it’s tempting to “set it and forget it.” You install a package or a plugin and move on. But software changes constantly, and security flaws get discovered all the time. If you’re not updating your systems, libraries, or frameworks regularly, you’re falling behind — and leaving known vulnerabilities in place. Having a habit (or even better, a system) for regular updates can protect you from a lot of avoidable trouble.
Then there’s the mistake of not encrypting sensitive data. Sometimes people think, “We’re just a small company, who cares?” or “We don’t store anything that important.” But the truth is, even email addresses or usage data can be valuable to attackers. If your data is stored in plain text, you’re just handing it over if something goes wrong. Encrypt data at rest and in transit. It’s not hard these days, and most frameworks make it pretty straightforward.
Startups also often overlook access control. Everyone on the team gets admin access, just because it’s easier that way. But that increases the risk of mistakes — or even intentional misuse — and it makes it harder to know who did what if something goes wrong. Role-based access control is a simple concept: only give people the permissions they actually need to do their job. It’s cleaner, safer, and more professional.
Let’s talk for a moment about security testing — or the lack of it. Many startups skip proper testing altogether. Maybe they do some manual checks or rely on whatever their framework catches by default. But without regular scans, audits, or penetration tests, you don’t really know where the weak spots are. You don’t need a huge security budget to get started — even using free tools to scan your web app can help you spot obvious issues before someone else does.
Startup Security Checklist: 10 Essential Actions
Don’t know where to start? Here is a practical checklist to build your startup’s defenses from the ground up:
- Implement a Password Manager: Mandate the use of a password manager (like 1Password or Bitwarden) for all team members. No more shared logins or passwords in spreadsheets.
- Enforce Two-Factor Authentication (2FA): Secure all critical accounts (email, cloud infrastructure, code repositories) with 2FA.
- Secure Your Code Repositories: Make all repositories private by default. Use
.gitignoreto prevent secret keys from being uploaded and regularly scan for any exposed credentials. - Establish Role-Based Access Control (RBAC): Apply the principle of least privilege. Give team members access only to the systems they absolutely need for their role.
- Encrypt All Sensitive Data: Ensure customer data and internal sensitive information is encrypted both in transit (with SSL/TLS) and at rest (in your database).
- Automate Software Updates: Create a process for regularly updating all dependencies, frameworks, and plugins. Use tools that can alert you to known vulnerabilities.
- Vet Third-Party Services: Before integrating a new SaaS tool, review its security policies and grant it only the minimum necessary permissions.
- Conduct Regular Security Scans: Use freely available tools to perform basic vulnerability scans on your web applications and infrastructure.
- Train Your Team: Educate everyone on common threats like phishing and the importance of secure practices. Your team is your first line of defense.
- Create a Simple Incident Response Plan: Decide before an incident happens who to call and what steps to take. It doesn’t need to be a 50-page document, just a clear plan of action.