Søren Johanson

Founder-led API Security for B2B SaaS startups

Protect your APIs, win investor trust, and keep shipping at startup speed.

Book a 15-min Intro Call

EU-based · 10 yrs secure API design · Mentor & speaker

Trusted by innovators across industries

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Your APIs handle more data than your Series A competitors - and attackers know it.

Growing SaaS companies become targets as they scale. Complex authentication flows, multiple API versions, and expanding integration partners create security gaps that can derail enterprise sales or compliance audits.

Bulletproof API security isn't defensive - it's your competitive advantage: close enterprise deals faster, pass vendor security reviews, and ship integrations without fear.

Not sure if this applies to you? Take this 30-second security reality check
  • Could a single leaked API key expose your entire customer database?
  • Do you have undocumented endpoints from your MVP days still running in production?
  • Would your current API access controls pass a Fortune 500 vendor security review?
  • Can you prove to auditors that customer data is properly isolated across tenants?
  • Are your webhook endpoints vulnerable to replay attacks or data injection?

If you answered "maybe" or "I'm not sure" to any of these, your API security needs attention before your next enterprise deal or compliance audit.

How I can help

Three engagement levels - start with a fast Scorecard, tighten with a rapid fix sprint, and stay secure with a flexible retainer.

1. API Security Scorecard

Audit → board-ready PDF in 7 days

Starting from €12,000

  • Attack-surface map of every endpoint
  • Auth & access-control deep-dive
  • OWASP API Top 10 sweep (manual abuse-path testing)
  • Executive summary to share with your board
  • Free re-test within 60 days
View a sample report

2. Rapid Hardening Sprint

Close critical vulns & ship secure patterns in 3 weeks

Starting from €28,000

  • Hands-on fixes for top Scorecard findings
  • Secure auth, token & RBAC patterns implemented in code
  • Gateway policy hardening
  • Developer hand-off session & docs

3. API Security as a Service

Ongoing reviews, pre-release checks & fast SLAs

Starting from €4,500 / mo

  • Continuous endpoint monitoring & vuln triage
  • Pre-release reviews for new API features
  • Investor & enterprise security questionnaire support
  • Resources on API-sec best practices
Discuss Retainer Options

3-month minimum engagement

Note: As a professional courtesy, I offer a 30-day money back guarantee for any retainer services. If you feel like our engagement is no longer mutually beneficial, I will refund 100% of the money, no questions asked.

About

I've spent the last decade specialising in secure API design and implementation, helping companies build robust API architectures that scale without compromising security. My expertise lies at the intersection of API development, security architecture, and business risk management - ensuring that the APIs powering modern SaaS products can withstand sophisticated attacks while enabling seamless integration.

Throughout my career, I've led critical API security initiatives including:

  • Reimplementing a secure GraphQL API for a global app store backend, supporting millions of users while maintaining strict data protection standards.
  • Implementing zero trust architecture as team lead at a real estate startup, ensuring rigorous API authentication and authorisation at every access point.
  • Designing and implementing JWT and OAuth 2.0 authentication systems for an enterprise insurance platform, enabling secure data exchange while meeting strict compliance requirements.

My approach combines deep technical expertise in API security with practical business knowledge - understanding that secure APIs aren't just about protection, but about building customer trust and meeting enterprise requirements.

I'm expanding my training work to include API security workshops for development teams, building on my experience teaching at GFU Cyrus and mentoring developers at The Mentoring Club.

Besides consulting, I also work on notable projects such as SquadUtils.org, ProcrastinationTracker.com as well as Headless By Design.