Junior Web Technical Specialist InternLocation: Madrid, Spain, OnsiteTeam: Publisher SuccessPosition Type: InternshipAbout Refinery89Refinery89 is a Dutch AdTech company headquartered in Madrid, working with premium publishers around the world to optimize their programmatic advertising performance.Through advanced technology, data, and hands on technical support, we help publishers increase advertising revenue, improve efficiency, and gain greater transparency across their monetization stack.Our international team operates at the intersection of technology, digital advertising, data, and publisher operations.About the InternshipWe are looking for a Junior Web Technical Specialist 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 develop practical technical skills and explore a career around web technologies, troubleshooting, data, publisher support, and Technical Account Management.What You Will DoWebsite Troubleshooting
- Support 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.Publisher Monitoring
- Support 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 Performance
- Learn 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 Communication
- Create 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.
- Browser developer tools.
- JavaScript troubleshooting.
- Network requests and browser debugging.
- APIs and web technologies.
- 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 Skills
- Fluent professional English.
- 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.Your experience can come from university projects, bootcamps, internships, freelance work, personal websites, GitHub projects, or technical side projects.Preferred BackgroundWe are particularly interested in students, recent graduates, or early career candidates from areas such as:
- Computer Science.
- Software Engineering.
- Web Development.
- Programming.
- Information Technology.
- Telecommunications.
- Data.
- Engineering.A formal technical degree is preferred but not required if you can demonstrate practical technical experience.Internship EligibilityTo participate in this internship, you must be legally eligible to complete an internship in Spain.Candidates should be enrolled in an educational program or otherwise be eligible to complete an internship agreement through a university, educational institution, or training provider.Please confirm your internship eligibility when applying.Things That Will Help You Stand Out
- Experience building or maintaining websites.
- Experience troubleshooting JavaScript errors.
- Familiarity with the browser console.
- Familiarity with network requests.




- Experience working with APIs.
- Basic understanding of HTTP, requests, responses, and browser behavior.
- Exposure to databases.
- Git or GitHub experience.
- Personal technical projects.
- Experience helping users solve technical issues.
- Basic spreadsheet skills.
- Spanish language skills are considered a plus but are not required.
- Dutch language skills are considered a plus but are not required.Who This Internship Is ForThis internship could be a strong fit if:
- Something on a website stops working and your instinct is to investigate why.
- You are comfortable opening browser developer tools and inspecting what is happening behind a page.
- You have worked with HTML, CSS, and JavaScript through your studies, personal projects, or previous experience and want to apply that knowledge in a real business environment.
- You see an error in the browser console and want to understand what caused it.
- You enjoy solving technical problems even when you do not immediately know the answer.
- You like working with both technology and people.
- You want to gain professional technical experience without necessarily following a traditional software engineering path.ImportantThis is not a traditional software development internship.You will not spend your internship building applications, developing product features, or working as part of a software engineering team.The internship focuses primarily on web troubleshooting, technical investigation, publisher support, advertising technology, performance monitoring, and Technical Account Management.You will use HTML, CSS, JavaScript, browser developer tools, and other web technologies to investigate and understand technical issues, but the core focus is troubleshooting, learning, and technical support rather than software development.Interview ProcessOur interview process consists of three stages.1. Initial ScreeningA short introductory conversation with our recruitment team to understand your background, motivation, English level, internship eligibility, and technical experience.2. Team InterviewA conversation with the Hiring Manager or Technical Account Management team focused on your technical curiosity, web knowledge, problem solving approach, and how you investigate unfamiliar problems.3. Practical Technical ExerciseA practical exercise designed to understand how you approach website related technical problems and learn unfamiliar concepts.You are not expected to know AdTech before completing the exercise.We care about your existing web fundamentals, your reasoning process, your willingness to learn, and how you approach technical problems.LocationThis is an onsite internship based in Madrid, Spain.Join Refinery89If you are studying or starting your technical career, already have experience with HTML, CSS, and JavaScript through your studies or personal projects, enjoy understanding how websites work, and want to gain practical professional experience across web technologies, troubleshooting, data, and AdTech, we would love to hear from you.

📌 Jr. Web Technical Specialist (Intern) (Madrid)
🏢 Refinery89
📍 Madrid