Founding CTO

🚀 Founding CTO & Co-Founder: Connectivity Platform Infrastructure

eSIM | Telecom Infrastructure | Device Engineering | Platform Systems

🌍 Location: Remote / Global

📈 Structure: Full-time with vested equity

🎁 Equity: Meaningful founding-level ownership

Ringo is building a global connectivity platform powered by eSIM technology, enabling seamless international mobile data access without physical SIM cards. As we soft-launch our MVP and expand internationally, eSIM reliability, roaming performance, device compatibility, and telecom infrastructure partnerships are becoming core competitive advantages. We are looking for a Founding CTO & Co-Founder to architect and lead the technical backbone of the company, combining telecommunications infrastructure leadership, platform architecture, device engineering, and telecom partnership development. You will work directly with the founder to design, build, and scale a global telecom platform from the ground up.

As Founding CTO & Co-Founder, you will own the technical architecture, connectivity infrastructure, and telecom partnerships that power Ringo's platform. You will lead the development of the global eSIM infrastructure, device compatibility systems, and the core platform architecture while also negotiating and managing strategic partnerships with telecom providers, roaming hubs, MVNO partners, and connectivity platforms. This role requires both deep technical expertise and commercial capability within the telecom ecosystem.

⚙️ Key Responsibilities

📡 eSIM & Connectivity Infrastructure

Design, implement, and operate Ringo's global eSIM connectivity stack, including designing and validating eSIM profiles (MVNO and roaming) compliant with GSMA SGP.22, managing the Remote SIM Provisioning (RSP) lifecycle, optimizing eSIM profile structure and download performance across 3G, 4G, and 5G networks, executing OTA campaigns (eUICC updates, policy updates, steering logic), owning Steering of Roaming (SoR) logic across global networks, analyzing APDU logs and debugging Remote File Management (RFM) issues, and improving activation reliability across device, SIM, and network layers.

🏗️ Platform Architecture & Infrastructure

• Architect and build the core platform infrastructure powering Ringo's services by designing scalable backend