About Refinery89La siguiente información tiene como objetivo proporcionar a los posibles candidatos una mejor comprensión de los requisitos para este puesto.
Refinery89 is a Dutch AdTech company headquartered in Madrid, working with premium publishers around the world to optimize their programmatic advertising performance.
Web Developer InternLocation: Madrid, Spain, OnsiteTeam: Publisher SuccessPosition Type: InternshipEnglish C1/C2 Level: MandatoryAbout The InternshipWe are looking for a Web Developer Intern to join our Publisher Success team in Madrid.
This internship is designed for a student, recent graduate, or early career candidate who already has a foundation in HTML, CSS, and JavaScript and wants to gain practical professional experience working with websites, technical troubleshooting, data, and advertising technology.
You do not need previous AdTech experience. We will train you on the AdTech side from zero.
During the internship, you will work with real publisher websites, browser developer tools, HTML, CSS, JavaScript, advertising technologies, reporting platforms, and technical diagnostics while receiving support and guidance from experienced members of the team.
The internship is idóneo for someone who wants to strengthen their web development fundamentals while gaining experience in technical troubleshooting, website integrations, data, publisher support, and Technical Account Management.
What You Will DoWebsite TroubleshootingSupport the investigation of technical issues affecting publisher websites.
Use browser developer tools to inspect HTML, CSS, JavaScript, scripts, network activity, and browser errors.
Help identify issues related to page structure, styling, scripts, advertising tags, or website configuration.
Reproduce technical problems and investigate their likely cause.




Review browser console errors and network requests when diagnosing issues.
Gather the technical information needed before escalating more complex problems to senior team members.
Web Technologies and IntegrationsWork with HTML, CSS, and JavaScript across real publisher websites.
Help investigate how scripts and third party technologies interact with webpages.
Support the implementation and validation of advertising related website integrations.
Review website configurations and identify potential technical issues.
Learn how APIs, scripts, browser requests, and advertising technologies interact within modern websites.
Publisher MonitoringSupport the monitoring of publisher websites and identify unusual behavior.
Perform regular technical health checks.
Help spot problems affecting advertising performance or website functionality.
Investigate whether changes on a website may be affecting advertising delivery.
Learn how different components of a publisher website interact with advertising technology.
Data and PerformanceLearn to interpret advertising metrics such as CPM, RPM, fill rate, impressions, and revenue.
Identify unusual changes in performance.
Support investigations into whether an issue may be technical, commercial, or related to traffic.
Use data to support technical investigations.
Work with spreadsheets and internal reporting tools.
Technical CommunicationCreate clear technical handoffs including screenshots, URLs, browser information, and descriptions of the issue.




Learn to explain technical findings in simple and understandable language.
Support communication with publishers in English about technical issues and their resolution.
Collaborate with Technical Account Managers, developers, advertising specialists, and other internal teams.
What You Will LearnYou will receive structured onboarding and gradually develop knowledge in areas including:Advanced website troubleshooting.
HTML, CSS, and JavaScript in production environments.
Browser developer tools.
JavaScript troubleshooting.
Network requests and browser debugging.
APIs and web technologies.
Website integrations.
Google Ad Manager.
Prebid.
SSPs.
Programmatic advertising.
Advertising tags and website integrations.
Publisher monetization.
Reporting and performance analysis.
Technical Account Management.
You are not expected to know AdTech before joining.
Must Have SkillsFluent professional English (C1/C2). Practical knowledge of HTML, CSS, and JavaScript.
Basic understanding of how websites are structured and how front end technologies interact.
Some experience using browser developer tools to inspect websites, troubleshoot issues, or understand page behavior.
Strong technical curiosity.
Strong problem solving skills.
Comfort investigating unfamiliar technical problems.
Clear written and verbal communication.
Basic numeracy and confidence working with percentages and data.
Reliability and attention to detail.
A genuine eagerness to learn.
The confidence to say, "I don't know yet, but I can investigate."Professional Experience Is Not Required.
Preferred BackgroundComputer Science.
Software Engineering.
Web Development.
Programming.
Information Technology.
Telecommunications.
Data.
Engineering.
A formal technical d

📌 Web Developer (España)
🏢 Refinery89
📍 España