Senior PHP Developer (part time job)

📌 Job Title: Senior PHP Developer📍 Location: Warsaw, Poland (Remote with occasional visits to the office)🕒 Type: Part-time, 50% FTE📄 Contract Type: B2B (own company registered in Poland is required)Start date: 15.12.2025End date: 31.12.2026Sanoma Learning is the leading European learning company, serving over 20 million students in 11 countries. We offer printed and digital learning materials as well as digital learning and teaching platforms for primary, secondary, and vocational education. The development of our methodologies is based on deep teacher and student insight and really understanding their needs. By combining our educational technologies and pedagogical expertise, we create learning products and services with the highest learning impact. In our Technology organization, you will join the largest cross-cultural community of Sanoma Learning and contribute to the digital transformation and future of education in Europe.Work setup 🌍We offer a remote work model with occasional visits to the office for team events, training, and business trips - typically once per quarter.Project description 📝The Sanoma Pro Portal is a central digital hub that brings together Sanoma Pro’s educational services, user accounts, and learning environments into one unified experience. It serves teachers, students, and schools by providing secure access to digital materials, licences, classroom tools, and personal content - all through a single, intuitive interface. The project’s mission is to streamline how educators and learners access Sanoma Pro’s digital ecosystem by improving usability, reliability, and accessibility across all touchpoints.About The RoleWe're looking for a skilled Senior PHP Developer to join our team. If you are passionate about PHP and have strong experience with WordPress, this role could be a great fit. Key responsibilities:Design, develop, and maintain backend functionality for the WordPress-based Sanoma Pro Portal.Build custom plugins, REST API endpoints, and server-side logic supporting portal features such as authentication, license management, and user dashboards.Integrate WordPress with external systems (SSO, payment systems, internal APIs, learning platforms, CRM/ERP).Optimize backend performance, caching strategies, and database structure for scalability and peak-load stability.Ensure code quality through automated tests, code reviews, and CI/CD processes.Contribute to accessibility and WCAG 2.2 compliance from a backend perspective (e.g., data structures, content formatting logic).Resolve Jira tickets, estimate effort, and participate in sprint planning, refinement, and retrospectives.Collaborate with frontend developers, designers, QA engineers, and product owners in a cross-functional Scrum team.Maintain secure coding standards and ensure compliance with internal and regulatory requirements (GDPR, data handling policies).Must-have RequirementsStrong experience in WordPress backend development, including:✅Custom plugin development✅ WordPress hooks, filters, cron✅ REST API and WP-CLI✅ Excellent knowledge of PHP (7.x/8.x) and object-oriented programming.✅ Experience with MySQL/MariaDB, query optimization, and database architecture.✅ Experience working in Scrum teams and using Jira for task management.✅Understanding of backend caching concepts (Redis, object caching, transient API).✅Knowledge of secure coding practices and data protection standards.✅Ability to read and work with documentation, including API specs and system integration guides.✅Understanding of backend caching concepts (Redis, object caching, transient API).✅English proficiency: B2/C1 (both written and spoken communication).Nice-to-Have Requirements💠 Comfortable with Git and branching strategies (GitFlow or trunk-based).💠Familiarity with headless WordPress or API-driven architectures.What We OfferAs an employer, Sanoma offers a working environment where you are able and encouraged to show your best self. The working environment is result-oriented as well as flexible with a focus on collaboration. We offer you a key position with interesting and challenging tasks and excellent opportunities for professional growth. You will be part of a highly professional and experienced international team in an open and informal setting, where initiative is expected and rewarded.