Senior Engineer, Core Network
Airalo
Romania
Posted on Mar 20, 2026
Ready to make travel easier for millions? Airalo is the world’s first and largest eSIM store, helping travellers stay connected seamlessly in over 200 countries and regions. We trust our teams to take ownership, put customers first, and do work that has a real impact every day. What’s in it for you? Airalo offers team members a range of perks, including remote work, generous PTO, wellness and learning allowances, and, of course, our annual Airalo Away retreat. Learn more about our benefits here; www.notion.so/airalo-public/Benefits-25396a97ffca81fb9bc1f0be479f1be3
Hi, I'm Daniele, VP of Engineering at Airalo!
Engineering drives Airalo’s eSIM platform. We build the product that lets millions of people connect instantly across the globe. The challenges are exciting: high-scale systems, carrier integrations, and products spanning both B2C and B2B. What matters most to us is creating an environment where engineers can do their best work. Real ownership, autonomy, and a direct link between what you ship and business outcomes are key. You’ll work with smart, motivated people who take their craft seriously. If you want to build things that matter at global scale, this is where you do it.
Airalo’s fully remote Engineering team is growing. In this role, you'll tackle complex technical challenges across our product ecosystem, helping build, innovate, and scale the platform that keeps millions of travellers connected worldwide.
As our Senior Core Network Engineer, you aren't just maintaining servers; you are the architect of a borderless world. You will own the evolution of our global Packet Core, ensuring a traveler in Tokyo has the same seamless 5G experience as someone in London. If you enjoy the 'detective work' of deep-dive signaling analysis and the 'architect work' of building scalable 5G systems, this is your next challenge.
Your main responsibilities will be:
- You’ll lead the design and growth of our Packet Core (EPC/5GC), ensuring our network scales effortlessly as our global traveler base doubles and triples.
- You’ll be our primary architect for global connectivity, managing roaming coverage through IPX/GRX providers and securing bi-lateral agreements that keep our users online everywhere.
- You’ll dive deep into signaling procedures across 3G, 4G, and 5G NSA. When a connection fails, you’re the expert who decodes the "why" using tools like Wireshark to look under the hood of Diameter and GTP signaling.
- You’ll fine-tune critical network flows—from the moment a user "attaches" to the network to the creation of high-quality voice and data bearers—ensuring every byte is delivered with precision.
- You’ll lead design reviews and manage the "Acceptance Testing" (ATP) phase to ensure our partners deliver to the high standards our users expect.
Does this sound like you?
- You’ve spent significant time in the "engine room" of a Tier 1 Carrier, Mobile Operator, or a major Equipment Provider. You understand the stakes of a live, global network.
- You are fluent in the language of mobile networks. Whether it's legacy 3G (SGSN/GGSN), dominant 4G (MME/PGW), or the transition to 5G, you understand how these systems interlock.
- You have a rock-solid grasp of IP networking—BGP routing, subnets, and ASN management are second nature to you.
- You understand that "it’s always DNS." You have hands-on experience architecting the DNS hierarchy (S-NAPTR) that allows mobile nodes to discover one another across the globe.
Bonus Points
- You have practical experience working within the unique constraints and opportunities of an MVNO or MVNE environment.
- You are excited about the future of telco and have experimented with or deployed Cloud Native Network Functions (CNF) and containerized cores.
- You’ve worked with Local Breakout (LBO) strategies to ensure data takes the fastest path possible to the internet.
- You have a niche understanding of managing roaming through Sponsor IMSIs to expand coverage quickly and efficiently.
If you are interested in this position, please apply via the link.
By applying, you acknowledge and agree that, in case of successful application, Airalo may request to run background checks as a condition for entering into an agreement with you. Rest assured that these checks will only occur upon your prior consent and at the end of the selection process, and will be strictly limited to what is allowed under the laws that are applicable to you. All data that you share or that we collect in connection with such checks will be processed in accordance with our Privacy Policy, available here: www.airalo.com/more-info/privacy-policy?srsltid=AfmBOooBT0rXAj1FaNelZ3VfN0wvhwzvAoxdtHnOKSVETpiSjiXVuycy
We sincerely thank all applicants in advance for submitting their interest in this opportunity. Airalo is an equal-opportunity employer and values diversity, equity & inclusion. We do not discriminate on the basis of race, religion, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. We are committed to providing reasonable accommodations upon request for individuals with disabilities throughout our job interview process.