Java Developer – E-Invoicing Integration

About the Role

SRQ Companies is expanding its e\-invoicing technology platform, with a focus on Peppol\-based electronic invoicing and integration with ERP and accounting systems. We are looking for a strong **Java Backend Developer** to join our technology team and take responsibility for the development and maintainance of the application. The ideal candidate should have strong Java development experience and a good understanding of **SOAP, XML, web services, digital certificates and security**. Experience with Peppol, AS4, e\-invoicing or eDelivery standards is highly desirable. Key Responsibilities * Develop and maintain Java\-based components for **Peppol AS4 messaging and e\-invoicing**. * Integrate and customize established open\-source AS4 implementations * Work with **Apache CXF, Apache WSS4J and XML Security** where required. * Implement and troubleshoot: * AS4 messaging * SOAP / SOAP with Attachments * WS\-Security * XML Digital Signature * XML Encryption * RSA\-OAEP and related cryptographic algorithms * TLS and digital certificates * AS4 receipts and acknowledgements * Investigate interoperability issues between our AS4 implementation and Peppol Access Points / endpoints. * Work with **SMP/SML discovery**, participant identifiers, service metadata and Peppol network requirements. * Integrate the Java AS4 service with our existing **PHP\-based Muhasib platform through REST APIs**. * Develop reliable message handling including retries, error handling, logging, message tracking and duplicate detection. * Work with XML\-based invoice standards including **UBL and Peppol BIS/PINT**. * Support integration testing with Peppol test environments and external Access Points. * Analyse technical specifications and implement requirements from Peppol and relevant e\-invoicing authorities. * Maintain secure, scalable and production\-ready backend services. * Prepare technical documentation for the developed components. Required Technical SkillsEssential * 3\+ years of professional **Java development** experience. * Strong knowledge of **Java 11\+ / Java 17\+**. * Strong experience with **Spring Boot / REST APIs**. * Good understanding of **SOAP and web services**. * Strong knowledge of **XML, XML namespaces, XSD and XML processing**. * Experience with **digital certificates, keystores, TLS and public\-key cryptography**. * Experience troubleshooting complex integration and interoperability issues. * Good understanding of HTTP, HTTPS and networking. * Experience with Git and standard software development practices Experience with one or more of: * **Peppol** * **AS4 / ebMS3** * **eDelivery** * **OpenPeppol** * **Apache WSS4J** * **Apache CXF** * XML Digital Signature * XML Encryption * RSA\-OAEP * UBL / Peppol BIS / PINT * E\-invoicing platforms Pay: ₹600,000\.00 \- ₹720,000\.00 per year Application Question(s): * What is the Notice Period you have, if you are currently employed? Education: * Bachelor's (Preferred) Experience: * encryption, WS security \& Cryptography: 1 year (Required) * As4: 1 year (Required) * ebms: 1 year (Required) * Apache CXF: 1 year (Required) * Apache WSS4J: 1 year (Required) * Strong Java \+ SOAP/XML : 5 years (Required) Work Location: Remote