Digital Platform Developer

About us KIWI is not just a company, it's a revolution. Since 2019, we have been passionately committed to creating innovative solutions that improve people's lives, helping as many smokers as possible quit smoking. With our headquarters in Croatia and a rapidly expanding international presence, our goal is to become the reference brand in Europe and a global benchmark in the e-cigarette industry. Our products combine cutting-edge design, innovative technology and a strong commitment to sustainability, proving that changing the world is possible, one step at a time. KIWI is looking for a Digital Platform Developer to join its international team. Location: Buje, Croatia / Hybrid About the Role KIWI operates in the tobacco and vaping sector, a highly regulated market. We are looking for an experienced Digital Platform Developer to design, develop and maintain our new centralized customer identity and authentication platform. The platform will operate as an independent service, integrated with our e-commerce, community and ERP systems. You will build both the platform and its user-facing pages: the login and account-security pages and the customer account area. The selected professional will play a critical role in building a secure, scalable and reliable authentication infrastructure, ensuring seamless integration across platforms, secure user migration and compliance with security best practices. We are looking for a technically strong, security-focused developer with proven experience in identity management, backend development and production environments. Key Responsibilities Identity & Authentication Development Configure, customize and extend Keycloak, including authentication flows, themes, two-factor authentication (2FA), passkeys and brute-force protection. Implement secure authentication and authorization processes using OpenID Connect and OAuth 2.0. Develop and maintain Single Sign-On (SSO) and Single Logout (SLO) functionalities across integrated platforms. Ensure secure account linking and session management. Platform Integration & User Migration Develop integrations between the identity platform, Magento 2, Invision Community and other connected platforms. Implement secure migration of existing Magento credentials, enabling users to access the new platform without a mandatory password reset. Verify existing password hashes (legacy and Argon2id) and implement progressive rehashing to modern algorithms where needed. Develop the backend services and API integrations with Odoo behind the customer self-service features. Front-end: Login Pages & Account Area Build the login, registration, password recovery, two-factor authentication and passkey pages as Keycloak themes in React (e.g. Keycloakify), following the designs provided by our Design team. Build the customer account area for the first release (profile and security settings, registered devices) with the same React components, together with Design and the Digital Project Specialist. Ensure responsive layouts, accessibility and multi-language support (Italian, English, Croatian). Infrastructure, Security & Deployment Deploy and maintain the platform using Docker and Kubernetes. Implement monitoring, backup and recovery procedures. Identify and resolve security vulnerabilities, including findings from penetration tests. Ensure platform reliability, scalability and secure handling of user credentials and personal data. Maintain code quality through Git workflows, code reviews and automated testing. Required Qualifications 5+ years of experience in backend software development, including at least 2 years working with authentication and identity systems in production. Strong practical knowledge of OpenID Connect and OAuth 2.0, including Authorization Code Flow with PKCE, token management, sessions and logout mechanisms. Hands-on experience with Keycloak or equivalent IAM platforms (Zitadel, Ory), including configuration and customization. Practical experience building production front-ends with React and TypeScript. Solid understanding of credential security, password hashing (bcrypt, Argon2id), hash migration and OWASP authentication guidelines. Experience developing modules and integrations using PHP 8, Magento 2 and Invision Community. Proficiency with Docker, Kubernetes, PostgreSQL and Git. Experience with code reviews, automated testing and secure development practices. Strong analytical, troubleshooting and problem-solving skills. Preferred Qualifications Experience with Cloudflare and related security services. Experience developing Keycloak extensions in Java (SPI). Experience with Keycloak theme development (Keycloakify or FreeMarker). Previous involvement in large-scale user account migrations. Knowledge of performance optimization and load testing. Experience developing and maintaining high-availability authentication platforms. Compensation & Employment Terms Salary Range: € 35.000,00 – € 50.000,00 gross annually. Employment Type: Full-Time Employment. Working Model: Hybrid / Remote-friendly, with no mandatory on-site presence. Final compensation will depend on experience, technical expertise and qualifications. Selection Process Shortlisted candidates will be invited to complete a practical technical assessment (approximately 4 hours), followed by a 1-hour technical discussion. The assessment will take place in a dedicated test environment using fictional data and will include: Configuring two-factor authentication (2FA) and brute-force protection in Keycloak. Explaining and designing a secure process for verifying an existing Magento password and progressively rehashing it to a modern algorithm. Showing how you would build the login pages and the account area with shared React components (e.g. Keycloakify), starting from a given design. Discussing security considerations, potential vulnerabilities and implementation decisions. The evaluation will focus on technical expertise, security awareness, problem-solving skills and the ability to deliver reliable solutions in production environments.