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: training, mentorship, and room to grow — always.

• Take the time you need: extra vacation days, sick days, and time off when life calls.

• Get premium healthcare: private health insurance in Lithuania and Poland — fully covered.

• Protect your peace: enjoy free subscriptions to Calm, Headspace, and Mindletic, and our own resilience and mindfulness trainings.

• Own your fitness: in-house gyms, sport cards, online workouts, and personal guidance — on us.

• Pack your bags for workation: experience our company-wide trip abroad to the fullest.

• Work from anywhere: work from wherever keeps you in the zone.

• Celebrate your milestones: birthdays, weddings, and new family members — all deserve a gift.

• Parent with ease: children’s summer camps and flexibility around the schedule — because parenting never pauses.

• Join the party: team building and company events people talk about for months.

• Unlock Cyber City: coffee bar, open gyms, kids’ room, music room, massage chairs — our Vilnius HQ is yours to enjoy.

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 privacy@nordaccount.com. Should you prefer to opt out of the automated evaluation, please submit your application directly to career@nordsec.com.