Location: Remote, EU time zones
Team: Product / Development
Contract Type: Contractor
Contract Duration: 6 months, with possibility of extension
English Level: Professional fluency, C1/C2 mandatory
AdTech Experience: Mandatory
Reports to: CTO
This is a temporary 6 month contractor position, with the possibility of extension depending on business needs and performance.
Professional English proficiency is mandatory for this role.
Candidates must also have significant previous experience in programmatic AdTech. This is a senior position and is not suitable for candidates looking to transition into AdTech without prior industry experience.
Refinery89 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.
We are looking for a Senior Ad Tech Specialist to join our Product and Development environment and take ownership of complex technical investigations across live publisher advertising stacks.
This is a deeply technical role focused on diagnosing issues, reproducing problems, identifying root causes, validating solutions, and translating findings into clear specifications or fixes that our Development team can act on.
You will work directly with live publisher environments, Prebid, Google Ad Manager, Amazon APS, consent frameworks, SSP integrations, browser debugging tools, and the wider programmatic ecosystem.
The objective is simple: when something is not behaving as expected, you should be able to determine what is happening, prove why it is happening, and define what needs to happen next.
The role also supports Product decisions, roadmap prioritization, and technical go or no go decisions with evidence from real publisher environments.
• Own complex technical issues that Operations or Development teams have been unable to resolve.
• Investigate tag defects, rendering failures, consent issues, bid path problems, and unexpected revenue behavior.
• Reproduce issues using live publisher inventory and controlled staging environments.
• Identify root causes and distinguish structural limitations from configuration problems that can be resolved.
• Produce clear technical specifications or patched tag implementations before handing work over to Development.
• Investigate publisher implementations directly at browser level.
• Use Prebid debugging, network requests, browser consoles, HAR files, and consent string inspection to understand what is happening.
• Validate request ordering, consent propagation, and bidding behavior against the intended configuration.
• Confirm fixes in live environments before considering an issue resolved.
• Perform structured audits across publisher monetization stacks.
• Review areas including Prebid configuration, Google Ad Manager, Amazon APS, CMP and TCF implementation, floor models, ad units, identity solutions, video, SSP health, and bidder performance.
• Score findings and produce clear action plans prioritized by impact and severity.
• Track technical changes across Google, Amazon APS, Prebid.js, SSP partners, and the IAB Tech Lab.
• Assess how ecosystem changes may affect the Refinery89 stack and publisher implementations.
• Translate findings into clear technical recommendations.
• Escalate decisions when changes require Product or Development involvement.
• Support phased technical rollouts using clearly defined success metrics.
• Establish validation criteria and rollback conditions.
• Test implementations in staging environments before Development handoff.
• Monitor performance following deployment and validate results against agreed thresholds.
• At least 5 years of experience in programmatic advertising technology, preferably within publisher monetization or the supply side.
• Significant hands on experience diagnosing and debugging live advertising environments.
• Deep working knowledge of Prebid.js, including configuration, adapters, modules, identity solutions, floors, and debugging.
• Ability to inspect and understand bidder adapter source code when documentation alone is insufficient.
• Strong technical knowledge of Google Ad Manager, including line items, pricing rules, AdX, dynamic allocation, GPT implementations, and MCM models.
• Strong understanding of IAB TCF 2.x and GDPR consent mechanics, including how consent is propagated across Prebid, GAM, and Amazon APS.
• Understanding of OpenRTB and supply chain transparency standards including ads.txt, sellers.json, and schain.
• Strong JavaScript knowledge, with the ability to read, modify, and validate production advertising tags.
• Advanced browser developer tools skills including network inspection, HAR analysis, and console debugging.
• Ability to write structured technical documentation that a developer can execute without requiring extensive additional explanation.
• Professional English proficiency at C1/C2 level.
• Previous professional experience in AdTech is mandatory.
• Experience implementing or troubleshooting Amazon APS or TAM.
• Python or TypeScript experience for internal tooling.
• Experience with video advertising and outstream environments, including IMA SDK and VAST.
• Familiarity with identity solutions such as ID5, SharedID, UID2, or EUID.
• Experience working with Jira and Confluence.
• Previous exposure to LATAM or Dutch publisher markets.
This is not a commercial partnerships or sales position.
You will not be responsible for commercial negotiations, SSP relationship ownership, or partner outreach.
This is also not a traditional campaign management or trafficking position. Day to day ad operations and GAM campaign trafficking are not the primary focus of the role.
This role could be a strong fit if:
• You enjoy opening developer tools and understanding exactly what is happening behind an advertising implementation.
• When an issue cannot immediately be explained, your instinct is to investigate it methodically rather than guess.
• You are comfortable working across JavaScript, browser behavior, programmatic infrastructure, and publisher configurations.
• You can move between technical details and the larger business impact of an issue.
• You value evidence and reproducibility when making technical recommendations.
• You can clearly communicate complex findings to both technical and non technical colleagues.
• You are comfortable taking ownership of difficult problems that do not have an obvious answer.
Our interview process consists of four stages.
A short introductory conversation with our recruitment team to understand your background, experience, English level, AdTech experience, and motivation.
A live technical discussion based around a real Prebid or Google Ad Manager configuration.
A practical exercise designed to assess how you investigate, document, and solve complex AdTech problems.
A final conversation with the CTO and relevant team members.
• Remote working within compatible EU time zones.
• A temporary 6 month contractor agreement with the possibility of extension.
• 50% coverage of the standard Sanitas private health insurance plan.
• The opportunity to work directly on complex publisher monetization environments and real world programmatic infrastructure.
• An international team working across AdTech, technology, data, and publisher operations.
If you have spent years working inside programmatic advertising stacks, enjoy debugging the problems others cannot immediately solve, and want to work closer to Product and Development while remaining deeply connected to real publisher environments, we would love to hear from you.