Strength. Care. Growth
You’ll know A1 Bulgaria is the right place for you if you are driven by:
- Opportunities to learn and build your career.
- Meaningful work in a stable and fast-paced company.
- Diversity of people, projects, and platforms.
- A supportive, fun, and inspiring place to work.
Your daily routine would include:
- Design, deploy, operate, and optimize IMS & VoLTE/VoWiFi/VoNR voice core platforms for all A1 OpCos.
- Manage and optimize core elements, including P?CSCF, I?CSCF, S?CSCF, SBC, TAS, MRF, and MGW.
- Ensure stability, performance, and high availability of voice services 24x7.
- Troubleshoot complex SIP/Diameter signaling flows and perform root-cause analysis.
- Support device testing, interoperability testing, regulatory feature validation (e.g., lawful interception, emergency call routing), and new service introduction.
- Implement automation for configuration management, alarms, KPIs, and routine operational tasks.
- Develop scripts and tools to improve core network reliability and operational speed.
- Collaborate closely with vendors on upgrades, migrations, capacity expansion, and deployment of new features.
- Contribute to the transformation toward cloud-native IMS and Voice over 5G (VoNR).
We’ll know you can make it if you have:
- Strong expertise in 3GPP standards, IMS, VoLTE, VoWiFi, and SIP signaling.
- Deep knowledge of Diameter, RTP/RTCP, and other telecom signaling protocols.
- Familiarity with EPC and 5GC voice architecture and features, such as SRVCC and SMS over IP.
- Experience analyzing packet captures using tools like Wireshark and vendor-specific trace tools.
- Practical experience with automation tools, e.g., Ansible; Terraform is a plus.
- Scripting skills in Python, Bash, or similar languages.
- Ability to automate repetitive operational tasks and build dashboards or monitoring tools.
- Hands-on experience with virtualized core networks (VMware, KVM).
- Understanding of cloud-native architectures, containerization (Docker), and Kubernetes.
- Familiarity with CI/CD pipelines, microservices, and Git-based workflows is an advantage.
Nice to Have:
- Experience with 5G SA VoNR (IMS over 5GC).
- Knowledge of CSFB, OMR, and supplementary services.
- Hands-on experience with vendor platforms, such as Ericsson, Nokia, Mavenir, and Oracle SBC.
- Exposure to observability and monitoring stacks, including Prometheus, Grafana, and ELK.
- Experience building internal tools or APIs to support network operations.
Apply now!
Every internal candidate will be invited for an interview.
Every colleague, who has changed their position in the company, will receive an individual bonus of 1000 euro for an educational course of their choice.
Refer a friend for this position and get a bonus of 250 euro under the Employee referral program!
