Job Title: E-Invoicing Technical Integration ConsultantWe are looking for an E-Invoicing Technical Integration Consultant to support an early-stage digital invoicing project in Oman.This is a freelance advisory and technical support role at this stage. It is not a full-time development role. However, if the project progresses successfully, there will be potential for a longer-term technical role or expanded engagement.The consultant will support us in evaluating potential technical and infrastructure partners, but the role may also continue beyond partner selection into early technical planning, documentation review, security readiness, integration design, and implementation support.Role purpose:We need a practical technical advisor who can understand the backend and integration requirements of a regulated e-invoicing platform, support discussions with potential technology partners, review technical documents, and help us make informed decisions.The ideal candidate should be comfortable joining selected online meetings as our technical/integration advisor, speaking with partner technical teams, asking the right questions, and summarizing technical risks in clear business language.Responsibilities:Join selected online meetings with potential e-invoicing, Peppol, ERP, API, and infrastructure partners.Ask technical questions during partner discussions.Review API documentation, XML/UBL documentation, integration guides, security documents, and technical proposals.Assess partner architecture, API quality, integration model, scalability, SLA, support model, and implementation risks.Help identify vendor lock-in risks, data ownership concerns, archive migration issues, hosting risks, and security gaps.Support high-level technical design discussions covering application, integration, infrastructure, data, hosting, backup, and retention.Help review or prepare technical questions related to Fawtara-style e-invoicing, Peppol-style infrastructure, ERP/POS integration, invoice validation, status tracking, and error handling.Support early technical documentation and architecture planning if the project progresses.Advise on technical readiness for security and compliance requirements, including MFA, encryption, monitoring, incident response, hosting, backups, audit logs, and ISO 27001-related controls.Provide short written summaries after meetings explaining what is good, what is risky, what is unclear, and what should be asked next.Relevant experience:E-invoicing / electronic invoicingPeppol / OpenPeppolUBL/XML invoice formatsAS4, SMP, Access Point concepts, or eDeliveryZATCA / Fatoora, Egyptian Tax Authority e-invoicing, UAE e-invoicing, or other tax authority integrationsERP, POS, or accounting system integrationsAPI integration, REST APIs, webhooks, authentication, sandbox testing, and technical documentation reviewOdoo, SAP, Oracle, Microsoft Dynamics, Zoho, Tally, QuickBooks, or similar systemsSaaS platforms, multi-tenant systems, backend architecture, and cloud hostingSecurity basics such as MFA, encryption at rest, encryption in transit, SSL/TLS, audit logs, access control, monitoring, backup, retention, and incident responseISO 27001 or information-security documentation is a plusTechnical topics the candidate should be able to understand or discuss:High-level system architectureApplication, integration, infrastructure, and data layersAPI design and partner integration modelsInvoice creation, validation, submission, status updates, rejection handling, and retriesXML/UBL invoice structure and mappingERP/POS/accounting system integrationData hosting location, backup, retention, and archive strategySecurity monitoring, SOC/SIEM basics, incident response, and SLA expectationsVendor lock-in, data portability, and exit/migration planningTechnical evidence required for regulated compliance projectsIdeal candidate:Practical and technically strongComfortable joining live business/technical meetingsAble to explain technical matters simply to non-technical foundersExperienced in e-invoicing, ERP integration, API integration, XML/UBL, tax authority integrations, or compliance systemsAvailable on a freelance, contract, or part-time basisStrong English communication skillsArabic is a plus but not requiredExpected workload:Remote workPaid hourlyOccasional online meetingsPossible expanded role later if the project progressesPlease apply with:Your relevant e-invoicing, ERP, API, XML, or integration experienceAny experience with Peppol, ZATCA, Fatoora, Egyptian e-invoicing, UAE e-invoicing, or tax authority integrationExamples of similar projects you worked on