Join our team as
Core Network Architect - Advisor (Contract) · Senior · Saily
At Saily, we’re removing the hassle from getting secure data plans while traveling.
No roaming charges, no plastic SIM cards. Just fast, secure mobile data in 200+ countries. Join the team behind Lonely Planet’s #1 eSIM—built for explorers, powered by NordVPN.
Your impact? Helping people stay securely connected, wherever they go.
About the role
We're looking for an experienced Core Network Architecture Advisor to help us navigate the technical complexities of building and evolving our own telecommunications infrastructure.
This is an advisory + potentially hands on role. We're looking for someone with deep, practical experience in mobile core networks who can challenge our assumptions, review architectural decisions, identify risks, and help our engineering teams make informed technical choices.
You'll work closely with our engineering leadership and core network team, providing expert guidance when needed.
Main Responsibilities
Architecture advisory: Review and provide feedback on our mobile core network architecture, including packet core, roaming, signaling, and related telecommunications systems.
Technical consultation: Help our engineers navigate complex telco challenges, troubleshoot architectural problems, and evaluate potential solutions.
Technology decisions: Advise on build-vs-buy decisions, open-source versus commercial solutions, infrastructure choices, and architectural trade-offs.
Vendor and operator integrations: Provide technical expertise when evaluating vendors, integrating with mobile network operators, and designing interoperability between different telecom systems.
Risk identification: Help identify architectural weaknesses, scalability limitations, reliability concerns, and potential integration challenges before they become problems.
Industry expertise: Share relevant knowledge of telecommunications standards, established industry practices, and emerging technologies.
Knowledge sharing: Act as a technical sounding board for our engineering team, helping translate complex telecommunications concepts into practical recommendations.
Core Requirements
Strong professional background in mobile core network architecture and engineering.
Hands-on experience designing, deploying, operating mobile core networks in production environments.
Solid understanding of mobile packet core technologies (4G/LTE EPC and 5G Core), their components, and how they interact.
Practical knowledge of mobile network integrations, signaling, roaming, and connectivity infrastructure.
Ability to evaluate architectural approaches, explain trade-offs, and provide pragmatic recommendations.
Comfortable working with engineering teams in a consultative capacity rather than a management role.
Experience with MVNO, MVNE, or international roaming architectures.
Knowledge of IMS, VoLTE, VoNR, or other voice and messaging technologies.
Familiarity with eSIM technologies and remote SIM provisioning.
Experience with cloud-native telecommunications infrastructure, virtualization, or Kubernetes.
What we offer
🎓 Sharpen your edge
Growth is built into how we work. Extensive online and in-person training programs, access to platforms like Coursera and Skillshare, a mentorship program, and internal career moves when you’re ready for something new — your development has no ceiling here.
🌿 Take the time you need
Rest isn’t a reward — it’s part of the deal. Enjoy extra vacation days that grow with your time here, plus additional days off for sick leave, special occasions, and parenting.
🏥 Get premium healthcare
Your health shouldn’t be something you worry about. We provide premium private health insurance so you have peace of mind and fast access to care whenever you need it. Available in Lithuania and Poland.
🪷 Protect your peace
A peaceful mind isn’t a luxury — it’s the foundation. We provide free subscriptions to top-rated Calm and Headspace apps, offer resilience and mindfulness trainings, and run dedicated mental health events.
🏋🏻 Own your fitness
Feeling good shapes how you work, think, and create. That’s why we offer in-house gyms, Multisport and Urban Sport cards, and online workouts. Need something tailored? Our Physical Well-Being experts are here with group mobility sessions, fitness guidance, and one-on-one consultations.
🌴 Pack your bags for workation
Picture this: the entire company flies out abroad. The days are packed with workshops, activities, concerts, and real time together. It’s legendary. If you’ve heard stories, they’re probably true.
✈️ Work from anywhere
New surroundings spark new thinking. When you need a reset, switch location and work from wherever keeps you sharp, creative, and in the zone.
🎁 Celebrate your milestones
The moments that make life special shouldn’t pass quietly. Birthdays, work anniversaries, weddings, new family members — each is marked with a special gift.
👶🏻 Parent with ease
When you’re a parent, the juggle is real. To make it smoother, we organize summer camps for the little ones and offer flexibility that lets you show up both for your family and your team.
🎉 Join the party
It never gets boring here. Get ready for team buildings that bring people closer, year-round company events that are equal parts educational and energizing, and the highlights everyone waits for — our iconic summer and winter celebrations.
⭐ Unlock Cyber City
Whether Vilnius-based or visiting from remote, our Vilnius HQ is fully yours to enjoy. Need focus? Silent room. Need energy? Open gyms. Need a break? Game room, music room, coffee bar. It’s a modern workspace built with your comfort in mind.
Kindly refer to our Privacy Notice for Recruitment Candidates for comprehensive information regarding our data handling procedures throughout recruitment processes.
We expect all candidates to provide accurate and complete information during the recruitment process. While limited use of AI tools to refine application materials is acceptable, candidates remain fully responsible for ensuring that their submissions reflect their own qualifications, skills, and experience. Any failure to do so may negatively affect participation in the recruitment process. If broader AI assistance is allowed for a particular role or stage, we’ll let you know in advance.
By submitting your application, you acknowledge that it may be processed using automated tools for evaluation purposes. As part of our recruitment process, we may use an AI-based application review tool to help assess applications based on skills and experience relevant to the role. This technology is used to support - not replace - human decision-making, and every application is ultimately reviewed by a recruiter.
If you would like more information about how AI is used in this process or wish to exercise your rights under applicable data privacy laws, please contact us at [email protected]. Should you prefer to opt out of the automated evaluation, please submit your application directly to [email protected].
Congrats — we have received your application!
If your application is a good fit for our team, we’ll contact you directly.