Senior Core Network Engineer

Overview Cubic³ Madrid, Community of Madrid, Spain The Company Cubic³ provides advanced software-defined vehicle solutions to over 200 countries around the world. Our powerfully smart connectivity enables leading automotive, agriculture, and transportation OEMs to deliver innovative new services and fully compliant in-vehicle experiences that customers desire, regardless of local market requirements. We believe in leadership that supports empowerment and responsibility, while recognising and developing leadership qualities across Our Team. So, whether you’re interested in joining us as an individual contributor, manager, senior leader – or someone who aspires to growing into a leadership role – we look for people who are results focused, empathetic, visionary, empowering, and who ‘champion’ our cultures and values. The Role We’re hiring a Senior Core Network Engineer to own the reliability, scalability and evolution of Cubic³’s global core network. This is a senior, hands-on role combining advanced troubleshooting, architecture input, vendor and stakeholder leadership, and operational ownership across packet and circuit core domains (including VoLTE, IMS, HLR/HSS, messaging). You’ll lead complex integrations, drive automation and monitoring enhancements, and mentor junior engineers in a fast-paced IoT/telecom environment. Responsibilities Take end-to-end ownership for availability, performance and capacity of core network elements across global deployments. Lead root-cause analysis and resolution of high-severity incidents; coordinate cross-team incident response, post-mortems and preventative actions. Architect and implement network integrations and migrations (vendor, operator and cloud/virtualised platforms), providing technical leadership and best practice guidance. Drive improvements to monitoring, telemetry, alerting and observability (including expansion of network monitoring capability and alert tuning). Identify and deliver automation opportunities (CI/CD, scripting, configuration management) to reduce manual toil and accelerate deployments. Mentor and upskill junior/mid engineers; provide technical reviews, runbooks and training. Own vendor relationships for escalation, product roadmap alignment and delivery quality; lead vendor acceptance and integration testing. Collaborate with Product, Engineering, Security and Delivery teams on architecture, change control, risk assessments and adoption of new technologies (e.g., virtualised CNFs, cloud native, 5G core elements). Manage change/control processes, capacity planning, and lifecycle replacement for core elements. Ensure compliance with security, regulatory and operational standards; contribute to disaster recovery and business continuity planning. Participate in an on-call rota and provide out-of-hours support for critical incidents. Qualifications Required experience & skills 8+ years’ telecom/core network engineering experience (or equivalent), with demonstrable senior or lead engineer responsibilities. Deep hands-on experience with 3GPP core elements: HLR/HSS, DRA, STP, SMSC, GMSC, IMS Core, PGW/SGW, OCS, PCRF/PCF, AAA. Strong protocol knowledge: GTP (S8/S1), Diameter (S6a, Gx, Gy, Rx, Cx, Sh), MAP, RADIUS, SMPP, SIP. Proven track record implementing complex telecom integrations across multi-vendor environments. Experience with virtualised/cloud deployments (OpenStack, Kubernetes, CNF/VMs) and familiarity with cloud networking concepts. Advanced troubleshooting skills with packet capture tools (Wireshark) and experience with performance analysis and capacity planning. Scripting / automation experience (Python, Bash, Ansible, Terraform or similar) to drive repeatable operations. Strong documentation, runbook and process design skills. Experience managing vendor relationships and leading technical evaluations / acceptance testing. Excellent stakeholder and communication skills; able to present technical issues to technical and non-technical audiences. Track record mentoring and developing engineering teams. Flexible and resilient: able to work to tight timelines and participate in on-call rotations and occasional travel. Nice to have Experience with 5G core (AMF/SMF/UPF), V2X, NTN or IoT-focused core deployments. Certifications: e.g., CCNP/CCIE, 3GPP training, cloud provider certifications (AWS/GCP/Azure). Experience with observability stacks (Prometheus/Grafana, ELK) and network security tooling. New hires at Cubic are required to work onsite five days a week during their six-month probation period to get to know the company, their team, and our ways of working. After probation, we offer a flexible arrangement of up to eight work-from-home days per month, provided it aligns with business needs and performance standards. Cubic³ is an equal opportunities employer and committed to fostering a diverse and inclusive workplace. Additional Information We’re committed to equal opportunity in employment and to fostering an inclusive environment for all employees. #J-18808-Ljbffr