From Vibe Coding to Reality: Building a Full-Featured SaaS in Under a Month

The AI Revolution Is Just Beginning, and Vibe Coding Is Leading the Way

Since the vibe coding hysteria was all around and social media accounts like LinkedIn, X, and Instagram were flooded with different "cool apps," I was wondering if it is really possible to build a full-fledged web app which would function as at least a regular SaaS application. When I say full-fledged, I mean regular authentication, user profiles, a set of MVP features, and payment gateway integration such as Stripe, etc.

I've been vibe coding for the last few weeks, and here are my hands-on first-person experiences building a desktop-only SaaS using Replit and its AI agent.

The Journey to a Working SaaS Product

Foundation Building (Day 1)

The first set of features such as email authentication, Google authentication, user profile, and dashboard were ready in a matter of a few hours. This immediate progress demonstrated the extraordinary efficiency that AI assistance can bring to the development process, particularly for standard features that follow established patterns.

Email Service Integration Challenges (Days 2-5)

Since I bought a new domain name, taxformify.com, it took some time for me to integrate the email notification service. My account was blocked due to non-compliance with some of their rules. So I had to fix them before I actually could make the email service work. Specifically, as part of my user experience, I'm sending known confirmation emails and notification emails (transactional emails).

This highlighted an important reality: even with AI assistance, real-world constraints like service provider requirements still apply.

Scaling Complexity and AI Limitations (Days 5-13)

By this time, I had already built lots of features on both the client user and accountant user side. I can say the app was ready 65%. But the more the code base grew, the harder it was for the Replit AI Agent to deploy and fix certain functionality.

If I had not had prior experience, I would have been helpless and had no clue what to do. I had to dig into specific files and feature implementation logic and look for alternative solutions to be able to make it work. Moreover, the AI agent was kind of grateful to me for my findings and eventually deployed the feature I needed.

This phase revealed that AI coding assistants currently work best as sophisticated partners rather than autonomous developers.

Final Implementation and Ongoing Challenges (Day 14-present)

Besides one feature which the AI agent is having difficulty implementing, my app is ready and is live. It is free for now and in beta mode. But I will have to investigate and dig into possible alternative solutions or workarounds to achieve my ultimate goal of launching a full-fledged SaaS in a matter of 20-25 days with basically only the cost of usage of the Replit app.

Development Timeline in Detail

The foundation phase was remarkably efficient, taking just a single day to implement core functionality. During this initial day, I successfully built authentication systems (both email and Google-based), created user profile functionality, and established the main dashboard interface. This phase progressed smoothly with no significant challenges, demonstrating the power of AI assistance for standard development patterns.

The integration phase spanned days 2 through 5, focusing primarily on email service configuration and domain setup for taxformify.com. The primary challenge during this period involved compliance issues with the email service provider, which temporarily blocked my account. I needed to address these compliance requirements before successfully implementing the transactional email system for user notifications and confirmations.

The feature building phase was the longest, extending from day 5 through day 13. During this period, the application reached approximately 65% completion with substantial functionality built for both client users and accountant users. As the codebase expanded, I encountered the most significant challenge: growing complexity that increasingly limited the AI agent's effectiveness. This required more hands-on intervention and technical problem-solving from me as a developer.

The final finalization phase began on day 14 and continues to the present. The application has successfully launched in beta mode and is live for users to access. While most features are complete and functioning, one persistent feature remains challenging to implement even with AI assistance. This final hurdle represents the current focus of my development efforts as I work toward a complete product release.

The Result: A Functional Tax Processing SaaS

The completed application successfully achieves its core purpose: helping tax accountants streamline and automate their filing processes. You can visit my desktop-only web app and try it. What it does is it helps to simplify, accelerate, and automate tax filing for tax accountants and realistically saves between 20 to 30 hours per 100 clients served in time.

Conclusions on AI-Assisted Development

This experiment demonstrates that "vibe coding" can indeed produce practical, functional software when properly directed. However, it also reveals important nuances in the current state of AI development tools:

1. AI excels at implementing standard patterns and foundational components
2. Human expertise becomes increasingly important as application complexity grows
3. Real-world constraints still apply regardless of development approach
4. The most effective approach combines AI assistance with developer guidance

For those considering similar projects, this experience suggests that AI-assisted development offers tremendous potential for rapid prototyping and MVP creation, but still requires human direction to overcome inevitable obstacles and ensure quality.

The future of software development likely lies in this collaborative human-AI approach, where each contributes their strengths to achieve outcomes neither could accomplish alone as efficiently.

Key Takeaways About Vibe Coding for SaaS Development

• Speed: Initial development phases are remarkably fast with AI assistance
• Complexity: AI effectiveness decreases as codebase grows and becomes more complex
• Expertise: Prior development knowledge remains valuable for troubleshooting
• Practicality: Functional SaaS applications can be built in weeks rather than months
• Economics: Development costs are dramatically reduced, primarily limited to platform fees

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What has your experience been with AI-assisted development tools? Have you tried building applications using vibe coding approaches?