Description The Senior CRO Developer will be responsible for transforming experimentation hypotheses into concrete digital experiences, developing and implementing A/B tests, personalizations, and dynamic experiences through Adobe Target (or equivalent tools). Will work in partnership with UX, Analytics, and Marketing teams to ensure the flawless technical execution of each experiment and the integrity of collected data. Main Responsibilities Implement A/B, multivariate, and personalized experiences in Adobe Target; Translate experimentation briefs into functional and scalable technical solutions; Develop and inject front-end code (HTML, CSS, JavaScript) in a controlled manner without compromising site performance; Perform technical validation (QA/UAT) across different browsers, devices, and user scenarios; Diagnose and resolve rendering issues, flickering, and script conflicts; Work with Tag Managers (Adobe Launch, GTM, Tealium) for script and trigger management; Collaborate with Data and UX teams to continuously optimize the experimentation process; Produce clear technical documentation for each implementation and ensure traceability of changes. Technical Requirements Advanced proficiency in JavaScript, HTML5, and CSS3, with strong focus on DOM manipulation; Preferred experience with experimentation tools (ideally Adobe Target; others such as Optimizely, AB Tasty, VWO are also valued); Knowledge of Adobe Launch or other Tag Management solutions; Experience debugging with tools such as Adobe Experience Cloud Debugger, Chrome DevTools, and Target Trace; Understanding of concepts such as segmentation, targeting, events, and conversions; Ability to assess performance and technical impact of developed experiences; Basic knowledge of version control (Git) and good coding practices. Personal Skills and Competencies Technical autonomy and ability to manage multiple projects simultaneously; Strong analytical thinking and attention to detail; Good communication with non-technical teams (marketing, design, product); Results-oriented and committed to continuous improvement; Curiosity about new technologies for personalization and digital optimization; Ability to work in agile and collaborative environments. **Availability:** Immediate or within 30 days; **Requirements:** **Location:** Lisbon **Work Mode:** Hybrid