# Yassin Khalil

> Yassin Khalil is an independent software developer based in Barcelona, Spain. This site shows the products he has built (WhatsApp automation, an AI resume tool, an ordering app, a paperwork service and open research), how a project runs from first call to handover, and articles on what an MVP costs, how long it takes and who should build it. It is written for founders and small businesses who want a first working version of a product, generally scoped at €600 to €10,000.

## Pages
- [Home](https://ykhalil.com/): what he builds, selected work, about, process and technical practices.
- [Start a project](https://ykhalil.com/start/): a three-step brief with an optional budget range; replies are personal.
- [Articles](https://ykhalil.com/articles/): four long-form articles with interactive charts and sourced data points.
- [Full text for AI agents](https://ykhalil.com/llms-full.txt): every article in Markdown.

## Facts
- Location: Barcelona, Spain. Works remotely with founders and small businesses. Languages: English, French, Arabic.
- Services: SaaS MVPs, AI products, WhatsApp automation, internal tools, integrations and custom web applications.
- Typical project size: €600 to €10,000, scoped around one core workflow. Fixed price for version one, weekly demos, you own the code and accounts.
- Process: short call, written scope, weekly working demos, launch and handover.
- Products built: Kadensio, Rolefit, Brown Nose Coffee, BCN Student Concierge, AI Bust Odds (details below).

## Work
- [Kadensio](https://kadensio.com/): WhatsApp conversation platform for real estate and hospitality.
- [Kadensio for real estate](https://real-estate.kadensio.com/): qualifies buyers on WhatsApp and books viewings.
- [Kadensio for hospitality](https://hospitality.kadensio.com/): answers guests and manages reservations.
- [Rolefit](https://tryrolefit.com/): AI resume tailor that rewrites a resume for a specific job without inventing anything.
- [Brown Nose Coffee](https://brownnose.ykhalil.com/): mobile ordering and loyalty app prototype for a specialty coffee shop.
- [BCN Student Concierge](https://bcnstudent.com/): online residency paperwork service for international students in Barcelona.
- [AI Bust Odds](https://aibust.ykhalil.com/): open research and live dashboard on the odds and damage of an AI investment bust.
- [Source code](https://github.com/YassinKkhalil4/when-the-buildout-breaks): the AI Bust research repository.

## Articles

- [How I Build an MVP From Idea to Launch](https://ykhalil.com/articles/how-i-build-an-mvp.md): The ten steps I follow to take an MVP from a rough idea to a live product, what I leave out of version one on purpose, and what I need from you before I start.
- [How Long Does It Take to Build an MVP? A Realistic Breakdown](https://ykhalil.com/articles/how-long-does-an-mvp-take.md): A realistic MVP timeline, from a few days for a tiny tool to eight weeks or more for a complex first version, and the seven things that stretch it.
- [Freelancer vs Agency vs In-House Developer: Who Should Build Your MVP?](https://ykhalil.com/articles/who-should-build-your-mvp.md): An independent developer, a software agency or an in-house hire: when each one is the right way to build your MVP, and the questions to ask before you choose.
- [I Built an AI WhatsApp Lead Qualification Platform: Here’s How It Works](https://ykhalil.com/articles/ai-whatsapp-lead-qualification-platform.md): How Kadensio qualifies leads inside WhatsApp conversations: the workflow, how messy messages become structured data, and where AI should not be trusted blindly.

## Full text

- [All articles in one file](https://ykhalil.com/llms-full.txt): the complete text of every article, in Markdown, with each interactive chart written out as text.
- [Articles index](https://ykhalil.com/articles/index.md): titles, topics and reading times.

## Core entities, stack and credentials
- Person: Yassin Khalil, independent software developer, Barcelona, Spain. Profiles: [LinkedIn](https://www.linkedin.com/in/yassin-khalil/), [GitHub](https://github.com/YassinKkhalil4). Site: https://ykhalil.com/
- Education and experience (as stated on the About section): studying High-Tech Entrepreneurship at Harbour.Space University; interned at Madinet Masr, one of Egypt's largest listed developers. Works in English, French and Arabic.
- Languages: TypeScript, Python, SQL.
- Web and apps: Next.js, React, Expo, Fastify, FastAPI. Data: PostgreSQL, SQLite.
- Integrations: WhatsApp Business API, Stripe, Google Calendar.
- Infrastructure: Docker, Caddy, Linux, nightly encrypted backups.
- Engineering practices: sensitive data encrypted at rest with per-record keys and scheduled deletion; signed webhooks processed once through durable queues and idempotent handlers; automated tests on core paths; rate-limited public endpoints.
- Topics, linked to Wikidata: [software development](https://www.wikidata.org/wiki/Q638608), [web application](https://www.wikidata.org/wiki/Q189210), [WhatsApp](https://www.wikidata.org/wiki/Q1049511), [artificial intelligence](https://www.wikidata.org/wiki/Q11660), [large language model](https://www.wikidata.org/wiki/Q115305900), [chatbot](https://www.wikidata.org/wiki/Q870780), [business process automation](https://www.wikidata.org/wiki/Q5001911), [minimum viable product](https://www.wikidata.org/wiki/Q6017127), [sales lead](https://www.wikidata.org/wiki/Q1027146).

## Contact
- [Start a project](https://ykhalil.com/start/): a three-question brief; replies are personal.
- yassin@kadensio.com
- LinkedIn: https://www.linkedin.com/in/yassin-khalil/