Senior Staff Engineer – Voice Signaling

About Skylo
Skylo is a global Non-Terrestrial Network service provider based in Mountain View, CA, offering a service that allows smartphone and IoT cellular devices to connect directly over existing satellites.

Skylo's direct-to-device service is now live on millions of activated devices across five continents, with more than 60 million square kilometers of coverage, in partnership with multiple satellite operators, mobile network operators (MNOs), Tier-1 chipset makers, and OEMs. Devices connected over satellite are managed and served by Skylo's commercial NTN vRAN, featuring a 3GPP standards-based cloud-native base station and core. Skylo provides anywhere, anytime connectivity solution that seamlessly roams between terrestrial and satellite networks. Our focus is on enabling connected services for people outdoors and connected workflows across three main verticals: mass-market consumer devices, automotive, and industrial IoT.

This role is located in Espoo, Finland or Bangalore, India where we are onsite 3 days a week in the office.
Summary Of How You Will Impact Skylo
Skylo Technologies is hiring a Senior Staff Engineer – Voice Signalling & Cloud Services to join our software development team in Espoo / Bangalore. This person will play a key role in Architecting and implementing Voice Gateway Solution across NB-IOT. The right candidate will combine a depth of technical knowledge with a passion for creating best-in class Voice Gateway software solutions.

How You Will Contribute

• Lead the design and development of Voice Services over NB-IoT.
• Build and optimize Voice Gateway signalling components and media session setup.
• Implement CSFB-SS7 (I1 protocol) for integration with NTN carriers and 3GPP IMS Core.
• Develop scalable Voice Gateway Server with CSFB-I1 and SIP/SDP interworking functions.
• Integrate third-party SIP/SDP protocol stacks for seamless operation.
• Focus on optimizing voice services for low-bandwidth networks.
• Support thousands of SIP sessions with interworking to MNO SBC and IMS networks.
• Define and execute test cases, automation, and code coverage with QA teams.
• Oversee build and deployment processes using Jira, Jenkins, GCR/GKE.
• Ensure security best practices in development and deployment.
• Collaborate with platform engineering and cross-functional teams for streamlined development.
• Establish disciplined processes for timely, high-quality software delivery with robust testing.

What We Look For

• 8+ years of experience in software development using OOP and microservices.
• Bachelor's or Master's degree in Computer Science, Engineering, or related field.
• Expertise in CSFB, I1, SIP signalling, and 3GPP IMS standards for telephony services.
• Skilled in building SIP-based solutions using SIP stacks for proxy clients and B2B servers.
• Hands-on experience with VoIMS and SIP/IMS network implementation.
• Proficient in tools like SIPP and FreeSWITCH for test environments.
• Programming expertise in C/C++, Go, or Java with strong SQL schema and query skills.
• Knowledge of stream processing (GCP Pub/Sub, Kafka) and REST API design.
• Experience with scalable distributed systems and horizontal scaling.
• Familiar with Kubernetes, Docker, Jenkins pipelines, and GCP tools.
• Strong understanding of code quality, performance metrics, and CI/CD tools (e.g., JMeter, Postman, Grafana, Prometheus).
• Collaborative team player with excellent communication skills.

What We Offer
With employees working across three continents, Skylo is proud to be an equal opportunity employer dedicated to building an inclusive and diverse workforce. Our worldwide and inclusive culture encourages a flexible approach to work, and we also offer an attractive range benefits such as:

• Competitive compensation packages including a stock option based equity program
• Comprehensive benefit plans
• Monthly allowances for wellness and education reimbursement
• A generous time off policy, holidays, and the opportunity to temporarily work abroad
• Once in a lifetime opportunity to be a part of developing and running world's first software-defined direct-to-device satellite network and service
• Access to world-class team and talent across tech domains: software, hardware, chipsets, telecom, satellite and network virtualization
• Open, transparent, inclusive culture that blends the Silicon Valley, Nordic and South Asia characteristics

EEO Statement
Skylo is an equal-opportunity employer and we celebrate diversity. We do not discriminate on the basis of race, religion, color, ancestry, national origin, caste, sex, sexual orientation, parent or caregiver status, political affiliation, gender, gender identity or expression, age, disability, medical condition, pregnancy, genetic makeup, marital status, or military service consistent with applicable federal, state, and local laws.

We are also committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. Please let us know if you need assistance or accommodation due to a disability.