Authentication insights from 70+ SaaS founders

What’s the real cost of overlooking authentication in a SaaS startup?

Lost deals, overworked engineers, and growing technical debt—these are just the beginning.

In 7 out of 10 enterprise deals, authentication requirements like SSO or SCIM are deal-breakers.

From my conversations with 70+ SaaS founders, one clear pattern emerged: authentication is often deprioritized until it becomes a deal breaker. The result? Delayed enterprise deals and overloaded engineering teams.

When done right, authentication is a strategic enabler of growth—accelerating enterprise deal cycles and building customer trust.

This blog distills those conversations into actionable insights—common pitfalls to avoid and strategies to help SaaS startups navigate their auth journey effectively.

Insights from 70+ SaaS founders on authentication

Here are grouped insights and anonymized quotes. Each group reflects common themes or challenges SaaS startups face in their authentication journey:

1. Growing pains: Moving upmarket brings new challenges

Many early-stage startups focus on building their core product and postpone investing in robust authentication until enterprise requirements arise. As startups begin moving upmarket, they encounter new demands for authentication that their current solutions cannot handle.

Insights:

• In the initial days, SaaS teams often stick to email-password authentication or basic social login (e.g., Google, Facebook).
• SSO (e.g., Okta, Entra) becomes a frequent customer request with mid-market and enterprise customers
• Startups often struggle to build robust user management systems, including invite flows and RBAC.

Founders say…

• “We’re using AWS Cognito right now, but enterprise customers are asking for SCIM and SSO—we’re not ready.”
• "We used Firebase for auth because it was straightforward and affordable when we were starting. But now, with enterprise customers asking for features like multi-tenancy and RBAC, Firebase just doesn’t cut it anymore."

2. The build vs. buy dilemma

Many startups debate whether to build authentication in-house or adopt third-party solutions. The decision is often influenced by costs, technical complexity, and the scale of enterprise demands.

Insights:

• Founders who build in-house often underestimate the long-term maintenance and security requirements.

Founders say…

• “We spent three months building SSO ourselves, and it still breaks with every new customer.”
• “We built most of our auth in-house but don’t have invite flows or advanced RBAC figured out yet.”

3. The hidden cost of authentication

Startups underestimate the long-term costs of authentication, from maintenance to migration and opportunity costs.

Insights:

• Building in-house often results in unexpected costs for security updates, compliance, and ongoing support.
• Migrating to a new system later is 2–3x more expensive than initial implementation.

Founders say…

• “We thought building auth in-house would save money, but the migration costs are now double what we spent initially. Also, maintaining our homegrown solution eats up 30% of our engineering team’s time.”

4. Frustrations with incumbent auth solutions

Even well-established authentication platforms like Auth0 or WorkOS have limitations, and founders often experience issues with cost, support, or feature gaps.

Insights:

• Pricing for enterprise use cases can be prohibitive. Those who adopt third-party solutions like Auth0 or WorkOS frequently cite high costs or gaps in features tailored to B2B needs
• Migration from initial authentication systems (e.g., Firebase, Cognito) to enterprise-grade solutions is expensive and time-consuming.
• Support and reliability concerns of some of the auth solutions push some startups to consider alternative solutions.

Founders say…

• “Auth0 works, but their pricing model is prohibitively expensive for our needs”

5. Key Recommendations

If I had to sum up 70+ conversations into a single slide of top takeaways, this is how it would look like. B2B SaaS companies acquiring enterprise customers need a quick and ready-to-launch SSO solution with auth workflows that support B2B scenarios.

As much as building with solutions like AWS Cognito and Firebase may seem lucrative, a detailed breakdown of a workable auth solution for your customers would be away from reality.

Authentication isn't just a technical decision—it's a strategic choice that directly impacts your startup’s ability to scale, enter enterprise markets, and maintain engineering velocity.

This article is based on conversations with over 70 B2B SaaS founders and technology leaders at SaaStr Annual 2024. All statistics and insights reflect real-world experiences shared by founders who've built successful SaaS businesses.

FAQs

Why is SSO essential for moving into the enterprise market?

SSO is vital because enterprise deals require secure central management of user access. As startups scale they discover that basic email and password systems do not meet the security standards of mid market clients. Implementing SSO via protocols like SAML or OIDC allows customers to use their own identity providers like Okta. This shift reduces administrative work and builds the trust needed to close large contracts. Neglecting this feature leads to stalled sales cycles when security reviews find missing enterprise authentication requirements. This makes SSO a key requirement for market expansion for any growing software company.

What are common pitfalls when building authentication systems in house?

Engineering teams often underestimate the long term maintenance and security updates needed for homegrown authentication. While a basic login seems simple to build adding features like RBAC and multi tenancy adds technical debt. Founders report that maintaining these systems can consume thirty percent of engineering time. Homegrown solutions frequently break when onboarding enterprise customers with unique configurations. Choosing to build instead of buy results in higher costs during future migrations as the system struggles to meet modern compliance standards. This diverts focus from the core product and slows overall company growth for early stage software businesses.

How does authentication architecture impact engineering velocity over time?

Authentication architecture directly affects how fast a team can ship new features. When engineers must troubleshoot SSO connections or update security protocols manually their focus shifts away from the core product. A robust and scalable auth platform allows developers to integrate enterprise requirements quickly using standard APIs. By offloading the complexity of multi tenant management and identity federation teams can maintain a high development pace. This strategic choice prevents technical debt that typically forces startups to pause development for months to fix identity issues. Well designed architecture ensures long term engineering velocity and faster time to market.

Why should startups avoid basic solutions like Firebase or Cognito?

Initial affordability makes basic auth providers attractive for early stage startups. However these tools often lack essential B2B features like SCIM provisioning and deep multi tenant support. As a company moves upmarket the limitations of these platforms become apparent requiring expensive and time consuming migrations. Transitioning from a B2C focused provider to an enterprise grade solution can cost two to three times the original implementation investment. For startups targeting enterprise clients starting with a platform designed for B2B scenarios ensures long term scalability and avoids future technical roadblocks. This strategy saves significant time and money for the engineering team.

What is the role of SCIM in enterprise user management?

System for Cross domain Identity Management or SCIM is critical for automating user provisioning in B2B applications. It allows enterprise IT administrators to sync their employee directories directly with your application in real time. Without SCIM manual user management becomes a significant burden for both the customer and your support team as the organization grows. Providing SCIM capabilities ensures that access is immediately revoked when an employee leaves which is a non negotiable security requirement for many organizations. Implementing this early streamlines onboarding and strengthens your product security posture while satisfying demanding enterprise IT teams and security officers.

How do agentic workflows change traditional machine to machine authentication?

Modern AI agents and MCP servers require sophisticated machine to machine authentication frameworks to operate securely. Traditional static API keys are often insufficient for dynamic agentic workflows that require fine grained permissions and short lived tokens. Architects must implement secure identity standards that support delegated access and auditability. This ensures that AI agents can interact with internal systems or external APIs without compromising sensitive data. As AI becomes integrated into B2B SaaS robust M2M authentication strategies like OAuth2 client credentials or dynamic client registration become essential for maintaining a secure and scalable architecture for future automation and security needs.

What defines a strategic approach to B2B authentication design?

A strategic approach views authentication as a growth engine rather than just a login box. This involves designing for multi tenancy from the start and ensuring the architecture can support various identity providers. It also includes providing self service portals for customer IT admins to configure their own SSO settings. By reducing the friction of onboarding enterprise teams you accelerate the sales cycle and improve customer satisfaction. Strategic authentication design focuses on scalability and security compliance ensuring the platform evolves alongside business needs. This approach allows the product to remain competitive and attractive to large scale enterprise buyers globally.

Why do established auth providers often fail B2B startups?

Many incumbent authentication providers use pricing models that scale aggressively based on monthly active users or enterprise connections. This can become prohibitively expensive for B2B startups that need to support many small to medium sized enterprise clients. Furthermore some legacy solutions lack the specific B2B workflows needed for complex multi tenant environments such as organization specific policies or custom branding. Founders often find that these platforms have gaps in support and technical flexibility. This mismatch leads teams to seek alternative solutions that offer more predictable pricing and features specifically tailored for scaling B2B SaaS companies and their customers.

How does Dynamic Client Registration improve developer platform security?

Dynamic Client Registration or DCR allows for the automated setup of OAuth2 clients which is vital for building secure developer ecosystems. Instead of manually issuing client secrets DCR enables software components or third party integrations to register themselves programmatically. This reduces administrative overhead and minimizes the risk of secret leakage. For architects building AI agents or MCP servers DCR provides a scalable way to manage numerous unique identities across a distributed system. Implementing DCR ensures that each connection is uniquely identified and authenticated providing better visibility and control over who is accessing your critical application resources and sensitive backend data.