Solution Architect for Managed IoT Connectivity & Mobile Network Architecture

Company Summary: A1 Digital International GmbH & Co KG is leading to a sovereign digital future - together. With scalable services and innovative solutions in the areas of IoT, cloud and security, we are the ideal partner for digital projects in medium-sized businesses. A1 Digital currently supports more than 500 companies in their digital transformation. Our experts at our locations in Vienna, Munich and Lausanne are already working with the technologies of tomorrow today. This is a path we can only take together - join in Location: Madrid, Spain Purpose of the Role: As Senior Solution Architect for Managed IoT Connectivity & Mobile Network Architecture, you will be the technical counterpart to the Senior Technical Product Manager and responsible for the architecture of our Managed Connectivity platform, including mobile core network components and IoT connectivity features. You will design end-to-end IoT connectivity solutions across LTE, LTE-M, NB-IoT, 5G NSA/SA, and VoLTE, ensuring reliability, performance and security. You will collaborate closely with product management, platform engineering, A1 core network teams, device vendors, SIM/eSIM partners, and service delivery to translate product concepts into scalable technical architectures. Key Responsibilities: Mobile Core & Connectivity Architecture: - Design end-to-end IoT connectivity architectures based on LTE, LTE-M, NB-IoT, 5G NSA/SA, and VoLTE. - Define integration patterns with PGW/GGSN, SGW, UPF, HSS/UDM, PCRF/PCF, IMS/VoLTE, SMSCs, and GTP proxies. - Translate product roadmap items into technical designs - Drive architecture for APN design, private APNs, local breakout, edge routing, and multi-regional PGW/UPF deployments. SIM / eSIM / OTA Architecture: - Architect SIM/eSIM solutions including profile features, IMS/SMS configurations, USIM/ISIM structures, SM-DP+ onboarding, and provisioning flows. - Collaborate with SIM vendors on applet requirements, SIM refresh logic, IMSI handling, and

OTA campaigns. IoT Platform Architecture - Architect platform components enabling managed connectivity, including API gateways, provisioning engines, OSS/BSS integration. - Ensure scalable design for millions of devices across multi-operator deployments. - Ensure telecom-grade reliability including redundancy, failover and mobility resilience. - Implement IoT and mobile network security best practices. - Ensure compliance with telecom regulations, GDPR and roaming rules. Cross-Functional Collaboration: - Work with Product Management on feasibility of network features - Support pre-sales and customer teams on deep technical discussions. - Collaborate with A1 Group network teams on mobile core implementations Required Skills and Experience: - Degree in Telecommunications, Computer Science, Software Engineering or equivalent. - 5+ years of experience in mobile network architecture, ideally IoT/M2M. - Knowledge of LTE, NB-IoT, LTE-M, 5G NSA/SA, IMS/VoLTE call flows, roaming, attach/TAU, GTP-U/C. - Understanding of PGW/UPF, APN configuration, QoS profiles, PCC/charging and Diameter/SIP signaling. - Experience with SIM/eSIM technologies, USIM profiles, OTA provisioning and SM-DP+/SM-DS. - Familiarity with device behavior across IoT chipsets. - Ability to document complex network and software architectures. - Fluency in English and Spanish - German is a big plus (but not mandatory) Personal Attributes: - Telecom-savvy, analytical thinker with strong problem-solving skills. - Passion for mobile network evolution and IoT innovation, curiosity and drive to explore new 5G IoT innovations. - Able to bridge customer use cases with network capabilities. - Strong communicator for complex telecom topics. What we offer: - Office in Madrid - Autonomous working with room for architectural decision-making - Dynamic, international and innovative working environment - Professional growth and career development opportunities within the A1