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

Lead Engineer & Technical Lead at Custom AI Solutions LLC