Senior Mobile Network Performance Engineer (m/f/d)

Drives evidence-based analysis of mobile network performance across 4G and 5G, translating KPI, benchmark, crowdsourcing, field, and customer-experience signals into clear technical findings, improvement proposals, and fix validation. The role supports the end-to-end Performance → Action → Validation cycle across mobile domains. Analyze mobile network performance across 4G/5G with focus on customer-impacting KPIs search as accessibility, retainability, mobility, latency, throughput, voice quality, and service reliability. Identify performance gaps using multiple inputs, including benchmarking results, crowdsourcing, field measurements, network KPIs, samples, and customer-experience data. Convert performance findings into clear technical hypotheses, prioritized actions, and expected KPI impact. Perform cross-domain performance engineering across RAN, Core/IMS, transport, roaming, and device-related behavior from an end-user perspective. Support technical deep dives on major topics such as voice quality, data reliability, latency, handover/mobility, TCP continuity, and national roaming performance. Define and follow up performance validation plans for feature activations, software upgrades, parameter changes, and special network events. Audit whether proposed fixes from Architecture, Operations, or vendors are likely to solve the observed issue and validate the outcome after implementation. Support the creation of performance dashboards, engineering views, and management summaryes with clear linkage between KPI behavior and customer impact. Contribute to automation of recurring analysis, KPI correlation, and performance reporting workflows. Provide technical support for benchmarking and QoS/QoE topics where deep domain analysis is needed.

Completed university degree in Telecommunications Engineering, Electrical Engineering, Computer Science, Engineering Informatics, or a comparable technical field. At least 7-10 years of professional experience in mobile network engineering, performance engineering, optimization, or benchmarking, ideally within a mobile network operator, telecom vendor, or close industry related. Strong knowledge of LTE and 5G NR network performance, including accessibility, retainability, mobility, latency, throughput, voice quality, and service continuity. Solid understanding of RAN KPIs, feature impact, capacity and mobility behavior, and the relationship between technical KPIs and customer experience / QoE. Experience in balancing performance using multiple data sources such as network KPIs, field measurements, benchmarking, crowdsourcing, rehearsals, and customer-experience indicators. Good understanding of end-to-end mobile service behavior across RAN, Core/IMS, transport, roaming, and device-related impacts. Experience in cross-functional technical collaboration with engineering, operations, architecture, vendors, and other stakeholders. Ability to translate technical findings into clear recommendations, priorities, and management-ready conclusions. Strong analytical and problem-solving skills with a structured, evidence-based, and result-oriented working style. Confident communication skills and ability to challenge assumptions constructively in cross-domain environments. Strong English skills, both written and spoken; German is an advantage.

Attractive salary Strong community of team players Trusted working hours with flexible scheduling and the possibility of working mobile up to 40% Numerous further training opportunities online and offline Discounts on 1&1 products and various leisure activities Free drinks and fresh fruit Job-bike subsidy