Senior Engineer, Voice & Distributed Systems

We’re building an intelligent revenue and growth system for small Canadian businesses. It can move an authorized customer conversation from qualification through follow-up to a confirmed booking - autonomously, within the business’s controls and show exactly what happened. That sounds simple until the conversation moves between channels, a caller interrupts, a provider times out or a booking response goes missing. We want those moments handled with the same care as the conversation itself. The result should feel remarkably capable to a client partner and remain reliable when real customers use it. We’re looking for a senior engineer based in Ontario to work directly with the founder and own the engineering through a production release. Our target is a working, fully tested system ready for deployment with our first client partners immediately and with clean completion of receiving the required access. You should be able to start immediately and give this delivery the capacity it needs. The existing repository contains a Python/FastAPI and PostgreSQL foundation, architecture and tests. Temporal, LiveKit Agents, LangGraph and Qdrant are proposed choices, not a prescribed shopping list. We want you to inspect the code, use what earns its place and recommend changes where you can show a better path to the required result. You should have personally shipped both production voice or telephony and reliable backend systems. The work includes tenant isolation, consent controls, durable events, safe retries, voice interruption and handoff, CRM and calendar integrations, provider receipts, monitoring and recovery. We’ll expect reviewable code and evidence from end-to-end tests, including what happens when an external action succeeds but its response is lost. You’ll have direct access to the founder, quick decisions and meaningful influence over the engineering. We value someone who can challenge an assumption, explain the trade-off and keep moving. AI coding tools are welcome, you own the quality of what ships. Refinements and fixes needed to meet the agreed release criteria are part of the build. We would also like this engineer to stay involved after launch if the collaboration works well. Maintenance, technical support and future development would be covered by a separate commercial arrangement. To apply, please tell us. Tell and show us about a system you personally built that real businesses use in daily operations. What does it do, how long has it been live, what usage can you substantiate, and which parts did you own? Share a live product, an authorised customer reference or redacted production evidence. A code repository may support your answer, but is not sufficient on its own.
 What have you personally delivered in production across both voice or telephony and reliable backend workflows? These may be separate systems, be clear about each.
 Can you start immediately with the capacity to meet the 15-20 day target?
 What would you verify in the repository and provider accounts before committing to the delivery date? Which proposed stack choices would you keep or reconsider and why?
 We’ll be moving quickly with engineers who can demonstrate real market use, explain their own system/contribution and take clear ownership of the outcome.