---
title: "SEO, SEM & SERP Optimization - José DA COSTA"
description: "SEO, SEM and SERP analysis. France TOP 10 Carpediem affiliates, PageRank 5-6/10, 0.1-1% conversion rate. Organic search strategies across 260 multilingual websites (15 languages, 5 countries)."
locale: "en"
canonical: "https://portfolio.josedacosta.info/en/skills/seo-sem-serp"
source: "https://portfolio.josedacosta.info/en/skills/seo-sem-serp.md"
html_source: "https://portfolio.josedacosta.info/en/skills/seo-sem-serp"
author: "José DA COSTA"
type: "skill"
slug: "seo-sem-serp"
generated_at: "2026-04-23T15:45:12.439Z"
---

# SEO, SEM & SERP Optimization

**Technical competency** - CTO · Founder · technical director (Celiane) - Expert

## Competency description

SEO, SEM and SERP analysis. France TOP 10 Carpediem affiliates, PageRank 5-6/10, 0.1-1% conversion rate. Organic search strategies across 260 multilingual websites (15 languages, 5 countries).

## Personal Confidence

**Expert** - 5/5

Scale: 1. Foundational · 2. Developing · 3. Proficient · 4. Advanced · 5. Expert

This reflects my personal confidence in applying this competency in real-world professional situations, based on hands-on experience, continuous learning, and practical outcomes.

## Details

- Domain: Hard skill (technical)
- Source: CTO · Founder · technical director (Celiane)
- Confidence level: 5/5 (Expert)
- Category: software-dev

## Other technical competencies from the same diploma

- [Reverse Engineering](https://portfolio.josedacosta.info/en/skills/reverse-engineering.md) - Reverse engineering of Google, MSN and Voila.fr ranking algorithms. Custom algorithms to analyze the weight of each HTML element in SERP ranking. Adva
- [Fullstack Development](https://portfolio.josedacosta.info/en/skills/fullstack-development.md) - Built and maintained 260 websites from scratch in PHP/HTML/CSS/MySQL, including a custom CMS (WSG), scraping algorithms, automated content generation
- [System Architecture](https://portfolio.josedacosta.info/en/skills/system-architecture-design.md) - Designed the WSG (Web Site Generator) architecture capable of generating millions of pages, scraping systems, SEO analysis databases and automated sub
- [JavaScript Programming](https://portfolio.josedacosta.info/en/skills/javascript-programming.md) - JavaScript for interactivity across the 260-website network, form validation, DOM manipulation for affiliate modules.
- [Algorithms and Complexity](https://portfolio.josedacosta.info/en/skills/advanced-algorithms-complexity.md) - Scraping algorithms, captcha cracking by pattern recognition and automated content generation (spinning).
- [Databases](https://portfolio.josedacosta.info/en/skills/database-fundamentals.md) - MySQL database design, SQL queries, basic administration.
- [System Administration](https://portfolio.josedacosta.info/en/skills/system-administration-bts.md) - Web server administration, Apache configuration, hosting management.
- [Network Infrastructure Design and Management](https://portfolio.josedacosta.info/en/skills/network-infrastructure-design-management.md) - Basic network configuration, domain name and hosting management.
- [Scripting and Automation](https://portfolio.josedacosta.info/en/skills/scripting-automation.md) - First automation scripts, basic crontab usage.
- [Network Security](https://portfolio.josedacosta.info/en/skills/network-security-cybersecurity.md) - Network security basics, SSL certificates, basic firewall configuration.

## Acquired during: CTO · Founder · technical director

Software publishing company managing 260 multilingual websites across 15 languages and 5 countries. Monetized through SEO and affiliate marketing, generating 500K EUR net profit. Started at age 18.

[See full journey entry](https://portfolio.josedacosta.info/en/journey/celiane-founder.md)

Full interactive page with navigation: https://portfolio.josedacosta.info/en/skills/seo-sem-serp