Lead Engineer & Technical Lead

Lead Engineer & Technical Lead - AI Platform Custom AI Solutions | Remote (Brazil) | Independent Contract Engagement About the Role Custom AI Solutions is seeking an experienced independent Lead Engineer & Technical Lead to provide senior technical leadership across VoxaCor and BridgeNode . Engaged through your own registered Brazilian entity, you will operate as an independent technical lead - setting architectural direction, performing code review, and providing hands-on production engineering - while controlling your own methods, tools, and working schedule. VoxaCor is our AI voice and SMS platform built for high-volume, real-time communication. BridgeNode is the open-source AI conversation framework that powers it - every product CAIS builds runs on it. You will engage across both as the senior technical voice on the platform. AI-first development is core to how we build. This engagement suits an experienced technical lead who has shipped production AI systems and guided other engineers doing the same. If that is not your background, this engagement is not the right fit. Engagement Structure This is a business-to-business engagement, contracted through your registered Brazilian entity. As an independent contractor, you control how and when you perform the services, supply your own equipment, and invoice CAIS for work delivered. The engagement is structured as a long-term, renewable relationship based on agreed scope and deliverables - not employment. A registered legal entity in Brazil is required. This is a firm requirement and is not negotiable. Scope of Services • Provide architectural direction and platform design decisions across VoxaCor and BridgeNode • Perform code review and release-readiness assessments, advising on production deployment • Provide technical leadership and mentorship services to the engineering team • Deliver hands-on production engineering across the real-time AI voice pipeline: STT, TTS, LLM orchestration, and telephony integration • Design backend services, APIs, and data models supporting high-volume, multi-tenant production workloads • Contribute to product and feature planning - helping spec, scope, and pressure-test features alongside the CEO • Serve as senior technical representative in customer and partner discussions when engaged for that purpose • Contribute to the BridgeNode open-source framework and VoxaCor proprietary feature layers Tech Stack • Backend: Node.js, TypeScript, PostgreSQL, Docker • Frontend: React 19, TypeScript, Tailwind CSS, shadcn/ui, PWA • Voice & Telephony: Telnyx, Deepgram (STT/TTS), WebRTC, SIP • AI / LLM: Anthropic Claude, Google Gemini, Mastra orchestration • Infrastructure: Azure, GitHub Actions CI/CD, multi-tenant architecture Engagement Fee • Fees invoiced by your entity on an agreed schedule and paid in USD for services delivered • Equivalent of $70K-$90K USD annually - depending on experience Qualifications • 6+ years of full-stack engineering experience, including senior-level production ownership • Demonstrated experience leading engineers - setting technical direction, reviewing others work, and guiding release decisions • Production experience building and shipping AI-powered applications - not just prototypes - with the judgment to make platform-wide architectural decisions independently • Hands-on experience with LLM APIs (Anthropic, OpenAI, Gemini, or equivalent) and agent orchestration • Real-time systems experience: WebSockets, streaming APIs, or telephony/voice pipelines • Strong database and API design fundamentals with PostgreSQL, in a multi-tenant SaaS architecture • Fluent English - written and verbal - strong enough to collaborate asynchronously, represent engineering in customer/partner calls, and communicate clearly with a US-based team • Able to arrange reasonable collaboration windows with a US-based team (you set your own working schedule) • Registered legal entity in Brazil - required for the engagement (not negotiable) Strong Pluses • Experience leading or mentoring distributed engineering teams • Experience deploying or self-hosting open-source LLMs in private or air-gapped infrastructure environments • Prior work in voice AI, telephony platforms, or real-time audio pipelines • Experience with Mastra, Pipecat, or similar AI agent orchestration frameworks • Background in transportation, logistics, or dispatch software ecosystems • Portuguese fluency for collaborating with a Brazil-based team (English remains required) What We re Looking For The ideal candidate is a seasoned, independent technical lead who is still hands-on in the code. You ve earned the judgment to make architectural calls and defend them, you ve guided other engineers and made them better, and you ve advised on what ships to production. You re excited about AI not as a buzzword but because you ve run these systems in production and led teams doing it. You want an engagement where you set the technical dir...