Senior Developer

• Provide expert technical advice and troubleshoot complex issues on UNEP's corporate website, Starter Kit, and key web platform migrations.
• Review architecture, code, and configurations for significant or high-risk changes and guide developers on necessary corrections.
• Support the technical readiness of major releases and migrations, focusing on dependencies, security, performance, integrations, and rollback plans.
• Offer specialist support on Drupal architecture, reusable components, React/Next.js integrations, APIs, OpenSearch, and related platform features.
• Advise on technical standards and reusable implementation patterns to ensure maintainability and consistency across web platforms.
• Resolve priority production issues requiring senior developer expertise.
• Coach the designated replacement by reviewing systems, development workflows, deployment processes, and outstanding technical issues.
• Develop practical Drupal technical training materials and an operations manual for UNEP developers and the replacement.
• Create and maintain comprehensive technical documentation covering Drupal environment architecture, modules, themes, configurations, reusable components, integrations, APIs, search, deployment, dependencies, maintenance, and troubleshooting.

• A master's degree in computer science, information systems, software engineering, or related field, or a first-level university degree plus two additional years of relevant experience.
• At least five years of progressively responsible professional experience in web development, including significant senior-level experience with PHP and Drupal.
• Proven technical leadership experience managing complex websites or multi-site digital platforms.
• Strong expertise in Drupal architecture, themes, modules, configuration, reusable components, website migrations, and enterprise web platform modernization.
• Experience with JavaScript and modern front-end technologies, preferably React and Next.js.
• Experience designing and integrating APIs and working with enterprise search technologies such as Elasticsearch or OpenSearch.
• Strong knowledge of Git, code review, and CI/CD deployment workflows.
• Experience applying security, accessibility, performance, and maintainability standards to web platforms.
• Demonstrated ability to review developers' work, provide senior technical guidance, produce technical documentation and training materials, and transfer technical responsibilities.
• Fluency in English is required.
• Strong communication skills and ability to work effectively in a multicultural and international environment are desirable.

Apply on the employer's application page. The closing date for applications is Wednesday, 21 October 2026.