How I built an AI Resume Tailoring SaaS in 1 hour

Have you ever applied to 50 jobs in a day and realized you used the exact same generic resume for all of them?

Yeah, me too. And it rarely works. Applicant Tracking Systems (ATS) ruthlessly filter out resumes that don't match the specific keywords in a job description.

But manually tailoring your resume for every single job is soul-crushing. So, as a developer, I did what we all do: I automated it.

In just one hour, I built an AI Resume Tailoring SaaS that takes a generic resume, cross-references it with a job description, and spits out a perfectly optimized, hyper-targeted resume.

Here is exactly how I built it, the architecture I used, and how you can do it too.

🏗️ The Architecture: Keep it Simple, Make it Fast

When building a micro-SaaS quickly, you cannot waste time on complex boilerplate. You need a stack that lets you move at the speed of thought.

Here is what I went with:

• Framework: Next.js (App Router)
• Styling: TailwindCSS
• Design Trend: Glassmorphism
• The Brains: Google Gemini API

1. The UI: Glassmorphism with TailwindCSS

First impressions matter for a SaaS. If it looks like a 1995 HTML table, people bounce. I wanted a sleek, futuristic look, so I went with Glassmorphism.

With TailwindCSS, creating a glassmorphism card is ridiculously easy. You don't need custom CSS files; just stack utility classes:

<div className="bg-white/10 backdrop-blur-lg border border-white/20 shadow-xl rounded-2xl p-8">
  <h2 className="text-2xl font-bold text-white">Upload Your Resume</h2>
  {/* Dropzone component goes here */}
</div>

The bg-white/10 gives it a subtle transparency, backdrop-blur-lg creates the frosted glass effect, and the border-white/20 adds that sharp edge highlight. Boom. Modern UI in seconds.

2. The Brains: Integrating the Gemini API

To actually tailor the resume, I needed an LLM that is fast, cheap, and has a massive context window (resumes can get long). The Gemini API was the perfect fit.

The secret sauce isn't just sending the text; it's the prompt engineering. Here is the core logic:

import { GoogleGenerativeAI } from "@google/generative-ai";
const genAI = new GoogleGenerativeAI(process.env.GEMINI_API_KEY);
async function tailorResume(baseResume: string, jobDescription: string) {
  const model = genAI.getGenerativeModel({ model: "gemini-1.5-flash" });
  const prompt = `
    You are an expert ATS resume writer. 
    Here is a candidate's base resume: ${baseResume}
    Here is the job description they are applying for: ${jobDescription}
    Task: Rewrite the resume to highlight the candidate's experiences that best align with the job description. 
    - Incorporate keywords naturally.
    - Do not invent experience they do not have.
    - Format the output in clear Markdown.
  `;
  const result = await model.generateContent(prompt);
  return result.response.text();
}

3. Tying it all together

The user flow is beautifully simple:

1. User pastes their generic resume and the target job description.
2. The Next.js API route securely calls the Gemini API.
3. The UI displays a gorgeous, loading skeleton (thanks again, Tailwind) while waiting.
4. The tailored resume is streamed back to the user, ready to copy or download.

🚀 Skip the Grind. Launch Your SaaS Today.

Building the core functionality took an hour, but taking a SaaS from a "cool prototype" to a production-ready, bug-free, payment-integrated product takes weeks.

You have to handle edge cases, prompt injection, PDF parsing, rate limiting, UI polish, and Stripe webhooks.

I already did the hard work for you.

If you want to start generating revenue this weekend without spending 100+ hours wrestling with configuration, authentication, and bugs, I am offering the complete, QA-audited source code of this exact SaaS.

What you get:

Stop building boilerplates from scratch. Launch your AI SaaS today and start selling subscriptions tomorrow.

👉 Get the Complete Source Code for $99 Here

P.S. The price will go up as I add more features (like automated cover letter generation), so grab it now to lock in lifetime updates!