Security Best Practices by Startup Stage

A pre-seed founder asked me last week: “Should we implement zero-trust architecture from day one?”

No. You have two engineers and zero customers. You need to ship product, not build Fort Knox.

A Series A founder asked me: “Can we keep using shared admin passwords for our production database?”

Also no. You have 50 customers paying six figures each. Time to grow up.

Security needs scale with your company. Here’s what matters at each stage.

Stage 1: Pre-Seed / Pre-Product Market Fit

Team size: 1-5 people Customer count: 0-100 Focus: Ship fast, validate, iterate

What Actually Matters

At this stage, focus on security hygiene that prevents catastrophic mistakes. Don’t over-engineer.

Must-haves (do these now):

Use auth providers, don’t build your own
- Auth0, Clerk, Supabase Auth, Firebase Auth
- Gets you MFA, session management, password reset for free
- Cost: $0-100/month
- One startup built their own auth. Got hacked in month 2. Spent 6 weeks fixing it.
HTTPS everywhere
- Free with Vercel, Netlify, Cloudflare
- Not optional in 2026
- Takes 5 minutes to enable
Never commit secrets to Git
- Use environment variables
- Add .env to .gitignore
- Use .env.example for documentation
- I’ve seen API keys in public GitHub repos three times this year. All got abused.
Use password managers
- 1Password, Bitwarden for the team
- No sharing passwords via Slack or email
- Cost: $5-10/month per person
Enable MFA for critical services
- AWS, GCP, Azure (your infrastructure)
- GitHub (your code)
- Banking/financial accounts
- Email accounts
- Takes 10 minutes per service.

Total setup time: 4-8 hours Total monthly cost: $50-200 Risk reduction: 80% of common attacks prevented

What You Can Skip (For Now)

Don’t spend time on:

SOC 2 compliance (no one’s asking yet)
Penetration testing (nothing to test yet)
Security audits (premature)
Advanced monitoring (simple error tracking is enough)
Detailed security policies (you’re 3 people, you all know each other)

One pre-seed founder spent $15K on a security audit. Report came back: “You need customers before we can assess risk.”

The Pre-Seed Security Checklist

Use this as your minimum:

Auth via established provider, not homegrown
HTTPS on all domains
No secrets in Git (use environment variables)
Password manager for the team
MFA on AWS/GCP/GitHub/email
Basic error tracking (Sentry, Rollbar)
Database backups enabled (automated)
Staging environment separate from production

That’s it. Ship product. Get customers. Then level up security.

Stage 2: Post-Seed / Product-Market Fit

Team size: 5-15 people Customer count: 100-1,000 Focus: Scale product, grow team, prepare for enterprise

What Now Matters

You have customers who trust you with their data. You’re hiring people outside your founding team. Time to formalize security.

Add these practices:

Implement role-based access control (RBAC)
- Not everyone needs access to everything
- Engineers get prod read-only, deploy via CI/CD
- Support gets customer data access, not infrastructure
- Finance gets billing, not codebase
- Document who has access to what
Set up proper logging and monitoring
- Centralized logs (Datadog, New Relic, Cloudwatch)
- Alert on suspicious activity (failed logins, permission changes)
- Monitor error rates and latency
- Cost: $200-1,000/month depending on volume
Create an incident response plan
- What do you do if there’s a breach?
- Who gets notified? (CEO, customers, authorities)
- How do you contain the damage?
- How do you communicate?
- One-page document is fine. Just have something.
Document your architecture
- What systems do you have?
- How do they connect?
- Where is sensitive data stored?
- Use Excalidraw, Lucidchart, or even hand-drawn (seriously)
- Helps with incident response and onboarding
Start vendor security assessments
- Every new tool: Check their security page
- Do they have SOC 2, ISO 27001, or similar?
- Sign Data Processing Agreements (DPAs) for tools touching user data
- Maintain a vendor list (spreadsheet is fine)
Implement automated dependency updates
- Dependabot (GitHub), Renovate, Snyk
- Auto-update dependencies with known vulnerabilities
- Run npm audit / pip-audit weekly
- One vulnerability in a dependency cost a startup $40K in incident response
Add basic access reviews
- Quarterly review: Who has access to what?
- Remove access for departed employees immediately
- Audit admin accounts (probably too many people have admin)

Setup time: 40-60 hours over 2-3 months Monthly cost: $500-2,000 Value: Prevents 95% of security incidents

Preparing for Enterprise Sales

If you’re starting to talk to enterprise customers, they’ll ask:

“How do you protect our data?”
“Do you have SOC 2?”
“Can we see your security documentation?”
“What’s your incident response process?”

At post-seed, you probably don’t have SOC 2 yet (that’s fine). But you should have:

Clear answers to these questions
Basic security documentation
Evidence you take security seriously

For more on enterprise sales requirements, see When to Pursue SOC 2 Compliance.

The Post-Seed Security Checklist

Everything from pre-seed, plus:

Role-based access control implemented
Centralized logging and monitoring
Incident response plan documented
Architecture diagram created
Vendor security assessments process
Automated dependency scanning
Quarterly access reviews
Offboarding checklist (revoke all access)
Basic security documentation for enterprise prospects

Stage 3: Series A / Scaling

Team size: 15-50 people Customer count: 1,000-10,000+ Focus: Scale operations, win enterprise deals, prepare for due diligence

What Becomes Critical

You’re closing six-figure deals. Investors are doing due diligence. Security incidents could kill the business.

Level up to:

Pursue SOC 2 Type II
- Enterprises will require it
- Takes 6-12 months, plan ahead
- Cost: $50K-150K first year
- Use a compliance platform (Vanta, Drata, Secureframe)
- See our full guide: When to Pursue SOC 2
Hire security expertise
- Fractional CISO ($5K-15K/month)
- Or dedicated security engineer
- Or security-focused engineering manager
- Don’t try to DIY security at this scale
Implement advanced monitoring
- SIEM (Security Information and Event Management)
- Threat detection and response
- User behavior analytics
- Automated alerting for anomalies
Conduct regular security testing
- Annual penetration testing ($10K-30K)
- Quarterly vulnerability scans
- Code security reviews
- Bug bounty program if public-facing
Formalize security policies
- Access control policy
- Data classification policy
- Incident response policy
- Acceptable use policy
- Change management policy
- Required for SOC 2, useful regardless
Employee security training
- Onboarding security training
- Annual refresher training
- Phishing simulations (test your team)
- Security awareness program
- Cost: $20-50/employee/year
Implement secrets management
- HashiCorp Vault, AWS Secrets Manager
- Rotate secrets regularly
- No more .env files for production
- Audit who accesses what secrets
Set up disaster recovery
- Automated backups (already have this)
- Regular restore testing (probably don’t have this)
- Geographic redundancy if needed
- Document recovery procedures
- RTO/RPO targets (how long can you be down?)

Setup time: 200-400 hours over 6-12 months Monthly cost: $5K-20K (including SOC 2) Value: Enterprise deals you couldn’t close before, investor confidence

Preparing for Due Diligence

Series A investors will do technical due diligence. They’ll check:

Do you have SOC 2 (or are actively pursuing it)?
Is your security architecture sound?
Do you have proper access controls?
Can you handle a security incident?
Is there a single point of failure (bus factor)?

For comprehensive due diligence prep, see How to Pass Technical Due Diligence.

The Series A Security Checklist

Everything from earlier stages, plus:

SOC 2 Type II (in progress or completed)
Fractional CISO or security hire
SIEM and advanced monitoring
Annual penetration testing
Formal security policies documented
Employee security training program
Secrets management system
Disaster recovery plan and tests
Security review in code review process
Compliance automation platform
Regular security audits

Security for Different Industries

Your industry affects your security requirements:

B2B SaaS (General)

SOC 2 Type II (essential for enterprise)
GDPR if EU customers (see GDPR Compliance Guide)
CCPA if California customers
Annual pen tests

Healthcare / Healthtech

HIPAA compliance (mandatory)
Business Associate Agreements (BAAs) with all vendors
Extra encryption requirements
Stricter access controls
72-hour breach notification
Start at stage 1, can’t wait

Fintech / Payments

PCI DSS if handling payment cards
SOC 2 Type II
Extra strong authentication
Fraud detection systems
Regulatory compliance (varies by country)
May need dedicated compliance team

B2C Consumer Apps

GDPR for EU users
CCPA for California users
Clear, simple privacy policy
Easy data deletion
Transparency about data usage
Lower barrier than B2B but still required

Common Mistakes by Stage

Pre-Seed Mistakes

Building custom auth (“we’ll make it secure!”) - Use a provider
No HTTPS (“we’ll add it before launch”) - Takes 5 minutes, do it now
Sharing passwords via Slack - Use a password manager
Ignoring security completely - Basic hygiene now prevents disasters later

Post-Seed Mistakes

Not documenting anything (“it’s all in our heads”) - Write it down
Everyone has admin access - Implement RBAC
No access offboarding process - Ex-employees still have database access
Skipping vendor reviews - Using tools that aren’t secure

Series A Mistakes

Starting SOC 2 too late - Enterprise deal delayed 9 months
Treating compliance as checkbox - Auditors see through it
Not investing in security team - One person can’t do this alone
Poor incident response - Breach happens, team panics, customers leave

Cost Summary by Stage

Pre-Seed

Setup: 4-8 hours
Monthly: $50-200
One-time: $0

Post-Seed

Setup: 40-60 hours over 2-3 months
Monthly: $500-2,000
One-time: $2K-5K (tooling, documentation)

Series A

Setup: 200-400 hours over 6-12 months
Monthly: $5K-20K (including CISO, SOC 2)
One-time: $50K-150K (SOC 2 first year, pen test, etc.)

The Bottom Line

Security scales with your company:

Pre-seed: Basic hygiene. Auth providers, HTTPS, no secrets in Git, MFA on key services.

Post-seed: Formal practices. RBAC, monitoring, logging, incident response, vendor management.

Series A: Compliance and expertise. SOC 2, fractional CISO, advanced monitoring, regular testing.

The worst approach is doing nothing until you have a breach or lose a deal. The second worst is over-investing in security theater before you have product-market fit.

Right-size your security to your stage. Level up as you grow.

Need help figuring out what security measures make sense for your stage? Building your team and wondering about security roles? Book a call to discuss your specific situation.