PBX / VoIP Systems Architect (Fractional / Part-Time)

About Us

Yottavox® is building a new cloud-hosted PBX platform engineered for clarity, security, and modern scalability.

We are developing the platform from the ground up and are now seeking an experienced VoIP Systems Architect to guide the technical direction, validate decisions, and ensure our solution meets telecom-grade standards.

This role is ideal for someone who has already architected PBX or SIP platforms, understands the intricacies of real-world VoIP systems, and enjoys shaping clean, modern solutions without legacy constraints.

The Role

You will serve as the technical authority for all things VoIP, shaping the architecture, defining core patterns, and working closely with the founder, the design team, and our full-stack VoIP developer.

You won’t be coding full-time - your focus is architectural clarity, correctness, and guiding implementation.

Key Responsibilities1. Architecture & System Design

• Define the overall architecture for a multi-tenant cloud PBX platform.
• Shape SIP signalling flows, RTP/media handling, NAT traversal strategies, and call routing logic.
• Create foundational diagrams, domain models, and architectural documentation.

2. Technical Direction & Decision-Making

• Recommend and justify technology choices (Asterisk, FreeSWITCH, Kamailio/OpenSIPS, RTP/media servers, backend stack).
• Identify risks early and propose practical, scalable alternatives.
• Provide input into backend and frontend designs to ensure VoIP compatibility.

3. Oversight & Engineering Guidance

• Guide and review the work of the full-stack VoIP developer.
• Advise on implementation patterns for SIP, events, CDRs, recording, queues, IVR, and number routing.
• Ensure the system behaves predictably under load and follows telecom best practices.

4. Security, Reliability & Performance

• Define safe-by-default patterns for SIP/TLS/SRTP, fraud prevention, rate limiting, and access control.
• Ensure the architecture supports low latency, resilience, and future scalability.
• Advise on disaster recovery, redundancy, monitoring, and analytics requirements.

5. Documentation & Clarity

• Produce clear architectural documentation that supports efficient development.
• Document key decisions, flows, constraints, and rationale.
• Help create a system that is maintainable and easy for new engineers to understand.

6. Collaboration & Delivery Support

• Work closely with UI/UX during design and with engineering during build.
• Participate in milestone reviews and provide structured feedback.
• Assist in planning a vertical slice for early validation.

Required Experience

• Extensive experience architecting VoIP/PBX/SIP platforms.
• Deep understanding of SIP, RTP, NAT traversal, codecs, and media behaviour.
• Strong background with Asterisk, FreeSWITCH, Kamailio/OpenSIPS, or similar.
• Experience designing secure telecom systems using SRTP/TLS and fraud controls.
• Familiarity with cloud infrastructure, containerisation, and scalable system design.
• Ability to communicate complex VoIP concepts clearly and simply.

Desirable

• Experience with multi-tenant SaaS architecture.
• Knowledge of global trunking integrations and number routing.
• Understanding of call recording pipelines, CDR accuracy, and observability.
• Experience supporting early-stage or startup-style product builds.

Why Join Us

• Shape a brand-new PBX platform without legacy constraints.
• Flexible fractional engagement - ideal alongside existing consulting roles.
• Work directly with a founder who values clarity, quality, and efficient execution.
• Influence architecture from day one and help build a future-ready telecom platform.

Job Type: Fractional - Part Time / Contract

Benefits:

• Flexitime
• Work from home

Work Location: Remote