I built a tool to filter 700 listings for my job search. It got me a position as head of AI.

• Santiago Fernández de Valderrama Aparicio developed an AI tool to make his job search more efficient.
• The tool, called Career-Ops, evaluated 740 job listings based on his job experience.
• He said he landed 12 interviews and he's now head of AI at a software company.

This as-told-to essay is based on a conversation with Santiago Fernández de Valderrama Aparicio, a 42-year-old head of applied artificial intelligence at a software company who is based in Seville, Spain. It's been edited for length and clarity.

After founding a retail phone repair company 16 years ago, I realized my favorite part of the job was using software to automate operations and provide better value to our customers.

I decided that for the next chapter of my career, I'd go all in on AI. I started learning more about it and using it for my business before selling the company. I sold it because I wanted to work at a company where I could build things with peers. I quickly found that finding a job was a job itself.

I thought there was no better way to prove my skills than by building a tool that helped me search for a job. That's how Career-Ops started.

I built the tool using Claude Code from Anthropic over the course of six weeks with the magic of vibe coding, and I used my technical background to take a closer look when something seemed off. Building such a tool using Claude Code was a valuable skill for the jobs I was looking for.

Once it was finished, it evaluated more than 740 job listings for me and recommended that I apply to 66 open positions based on my experience and interests. Out of those 66, I got 12 interviews.

Ultimately, I accepted an offer as the head of AI at a company in April.

I released the tool to the public. Making it available to everyone helped me build my personal brand and land a job. I didn't feel comfortable monetizing it to people looking for a job because that's a basic need.

We're working to make the tool more accessible

Today, anyone can build things with AI. You don't need to code; you can use plain English. When I posted about the tool on Reddit, I got a massive response asking me to share the code publicly. That was a signal to me that this needed to be open source.

The main response I've gotten is gratitude, and the second one is people asking how they can use it themselves.

It's a bit technical to set up, so I made a Discord community for people to help improve Career-Ops and help each other use it. It grew to over 1,000 members within a week of launching in April. Together, we are working to make it more accessible, but once it's set up, you can talk to it like a chatbot on your device.

The better the system knows you, the better job listings it can provide. For example, a software engineer might tell Career-Ops that they want to build things with AI. It will come back to you with a list of listings based on job title and description.

It's the ultimate résumé booster

My vision is for job seekers to be able to filter companies using AI instead of the other way around. Ultimately, I see this as a platform where people upload their CVs and any other material related to their work, and companies could post their job offerings too, like a marketplace.

Although Career-Ops helped me narrow down jobs, it was the fact that I built it that landed me my job as the head of AI. It's like the ultimate proof-of-work. It's scaffolding; the ability to build my own tools to solve a problem.

Building in public is the new résumé. In the AI era, your side project is your portfolio.