Core Network Engineer

We are seeking a Core Network Engineer who combines hands-on experience operating telecom core network elements with the ability to integrate, source, and expose network data and capabilities via APIs.

You will be instrumental in supporting our platform, which enables telecom operators to provide network APIs (e.g., number verification, quality-on-demand, device status) to external developers and aggregators.

This role requires a solid understanding of 4G and 5G Core Network architecture, subscriber management systems, and policy/control plane nodes, along with familiarity in interfacing these systems through standard protocols and data exposure frameworks.

Core Network Expertise & Data Sourcing

• Act as the technical SME for the following network elements:
• Subscriber & Identity Systems: HSS, HLR, UDM, AUSF, EIR
• Policy Control & Routing: PCF, PCRF, DRA
• Packet Core: PGW, GGSN, UPF
• Security & NAT: CGNAT
• Understand how these nodes store and process subscriber session data, identity, and policies.
• Work with operator teams to define which data and services can be securely exposed via APIs.

API Integration & Enablement

• Design integration workflows to source information from network elements via:
• Diameter / HTTP/2 / RESTful interfaces
• 3GPP standardized APIs
• Custom vendor APIs or connectors
• Support implementation of API exposure layers (e.g., CAMARA APIs) and facilitate compliance with GSMA Open Gateway standards.

Data Mapping & Specification

• Map internal data structures to external API schemas (e.g., user location, device status, QoS parameters).
• Define technical specifications for API contracts and ensure data integrity and privacy.

Testing & Validation

• Validate integration workflows end-to-end, including:
• Querying test data from core network elements
• Verifying correct API responses
• Handling error scenarios
• Collaborate with development and QA teams to build robust test coverage.

Documentation & Knowledge Transfer

• Document procedures for sourcing and exposing network data.
• Train internal and external stakeholders on:
• How APIs interact with core network systems

How to troubleshoot connectivity and data flow issues.

• Bachelor’s degree in Telecommunications, Computer Engineering, or equivalent.
• 5+ years of experience working with telecom core network elements.
• Hands-on experience integrating with vendor systems (Ericsson, Nokia, Huawei, Cisco) preferred.
• Experience in projects involving API enablement or network function exposure is highly desirable.
• Core Network Expertise:
• In-depth understanding of:
• HSS, HLR, UDM, AUSF, EIR for identity and authentication
• PCRF, PCF, DRA for policy control
• PGW, GGSN, UPF for data plane functions
• CGNAT and session management
• Familiarity with 4G EPC and 5G Core (SBA) architecture
• Integration & APIs:
• Knowledge of:
• 3GPP standards for Service Exposure Functions (SEF)
• RESTful API principles
• Diameter and HTTP/2 interfaces
• OAuth2 and API security models
• Exposure to CAMARA / GSMA Open Gateway concepts is a strong plus.
• Tools & Scripting:
• Ability to create prototypes and test queries (Postman, Swagger, custom scripts)
• Comfortable with basic scripting in Python or Bash
• Soft Skills:
• Strong cross-functional communication (network teams, developers, product)
• Analytical mindset and structured problem-solving