Mobile Core Engineer (Sim for Things)

Proximus Global, combining the strengths of Telesign, BICS, and Route Mobile, is shaping the future of communications and digital identity.

Our mission is simple : to enable seamless global connectivity and trusted engagements that power the world's interactions.

Together, our solutions fuel innovation across the world's largest companies and emerging brands. With a truly global reach, we enable businesses to create engaging customer experiences while integrating fraud protection across the entire lifecycle.

Our portfolio covers global voice, messaging and data connectivity, alongside 5G and IoT solutions. It also includes digital identity, verification and CPaaS platforms for personalised, omnichannel engagement. Through these capabilities, we help businesses and communities stay connected, secure and ready to grow. Today, we reach more than 5 billion subscribers, secure over 180 billion transactions every year, and connect more than 1,000 destinations worldwide - delivering on our commitment to connect, protect and engage everywhere.

Key highlights

Powering more than 13 billion digital communications every month

Supporting over 3,500 active customers through a presence in 50+ global offices across 100+ countries

Managing 50% of global roaming data traffic and connecting 150 million IoT devices

Driving innovation in 5G, private networks and IoT, reinforcing our position in next-generation communications

Why Proximus Global?

Global & Inclusive

Work with diverse teams across 100+ countries, in a truly international and connected environment.

Ownership & Trust

Take initiative, make decisions and own your impact with real autonomy.

Innovation with Purpose

Contribute to meaningful solutions in global connectivity, combining technology, platforms and expertise across Proximus Global.

Growth Mindset

Continuously learn, challenge the status quo, and grow across our global organisation.

Please note: this role requires working from the Brussels office 2 to 3 days per week. It is not a fully remote position and is offered on a permanent contract (not freelance).

About the role

At Proximus Global, we’re looking for a Mobile Core Engineer to join our SIM for Things (SFT) team.

At Proximus Global, we’re looking for a Mobile Core Solution Design Engineer Expert to join our SIM for Things (SFT) team. In this role, you will lead and contribute to the analysis, design, development, and delivery of end-to-end mobile core solutions for IoT connectivity based on business, technical, operational, cost, time-to-market, and regulatory requirements.

Working at the intersection of technology, product, and operations, you will balance third-party/vendor solutions with internal development and integration work. From initial requirements and architecture impact analysis to the production launch, you will take end-to-end ownership across the project lifecycle, driving platform evolution and technology assessments. You’ll collaborate closely with cross-functional teams to ensure high-quality, scalable solutions and an exceptional customer experience.

What you’ll do

• Review and validate technical solutions to confirm they meet business, regulatory, operational, cost, time-to-market, and quality requirements.
• Lead technical platform development, shape the platform roadmap, maximize technology use, and perform technology assessments for future solution evolution.
• Lead or support end-to-end implementation projects across the lifecycle, coordinating with stakeholders on design, rollout, optimization, and ongoing maintenance.
• Draft and review detailed functional and technical specifications, as well as Request for Proposal (RFP) documents.
• Drive architecture and impact analysis, developing methods, procedures, and technical documentation for product, marketing, and operational teams.
• Engage directly in the implementation and deployment of technical solutions in close collaboration with operational teams.
• Act as a respected technical authority and reference point, applying call-flow analysis and troubleshooting expertise to support internal and external stakeholders while building credibility and trust.

What you bring

Experience & technical expertise

• Engineering degree preferably in Telecommunications, or a related field.

  At least 10 years of professional experience in a telecom or IT environment.

• Solid understanding of the overall telecommunications, mobile core, and IT landscape.
• Proven experience in designing and deploying mobile core network solutions across traditional and cloud-based environments (AWS, Azure, or Google Cloud).
• Deep experience with IoT / M2M connectivity platforms (including SIM for Things) and multi-tenant environments with large-scale device connectivity.
• Technical proficiency in key network protocols and signaling: HTTP, SS7, Diameter, MAP, INAP, and GTP.
• Strong expertise in SIM/eSIM technologies: SIM applets, Over-The-Air (OTA) management, Remote SIM Provisioning (eUICC, SM-DP/SM-SR, SM-DP+, GSMA SGP.31/32), SIM file systems, and provisioning/ordering workflows.
• Strong background in roaming, IoT/M2M, and MVNO/MVNE environments.

  End-to-end view of mobile core architecture, call flows, and deep-dive troubleshooting.

• Hands-on knowledge of two or more mobile core components across 2G, 3G, LTE, and 5G networks (e.g., P-GW/GGSN, HSS/HLR, PCRF).

Nice to have

• Knowledge of the international carrier business.

Your soft skills

• Strong communicator with excellent presentation, negotiation, and interpersonal skills, capable of explaining complex technical concepts to different audiences.
• Collaborative team player, comfortable coordinating work flexibly across departments in an international and culturally diverse environment.
• Customer-focused and solution-oriented with a strong sense of ownership and determination to deliver projects on time and meet expectations.
• Analytical thinker and problem solver with strong planning, organization, and project management capabilities.
• Proactive approach to risk management, with an eagerness to learn autonomously and grasp existing solutions quickly.
• Comfortable navigating technical complexity and prioritizing effectively.

Your Benefits

• A competitive base salary and short-term incentives, including a yearly bonus linked to individual and company performance
• Comprehensive insurances including hospitalization insurance, outpatient care insurance, life insurance, disability insurance and travel insurance, fully funded by PXG
• A supplementary pension plan, fully funded by PXG
• A flexible mobility package including a company car or car allowance, a mobility budget for flexible commuting including a fuel card, bike lease options, etc.
• A telco offer including free internet at home, budget for a mobile phone, a monthly phone plan and many discounts on the Proximus products catalog
• Additional benefits such as meal and eco vouchers, 32 vacation days, corporate discounts through Benefits@Work, …
• Wellbeing at work: yoga and pilates classes, corporate events, etc.

Discover Proximus Global

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