Black Umbrella AI builds and deploys AI voice agents for businesses that are tired of leaky pipelines, missed follow-ups, and no-shows killing their ROI. We specialize in end-to-end Retell agent setup for companies that want production-grade calling infrastructure without the DIY learning curve. What makes us different: we come from the marketing side of the table, not just the engineering side. Our founder has 10+ years in direct response and has managed over $50M in ad spend across 30+ verticals, so we don't just build agents that talk, we build agents that convert. Every Retell deployment we ship is engineered around pipeline velocity: more conversations, better qualification, faster booked calls. Our agent setup service includes voice and prompt engineering, objection handling frameworks pulled from real sales floors, full integration with GoHighLevel, n8n, and your existing CRM stack, plus post-launch testing and optimization. We offer both done-for-you builds and white-glove training for teams that want to run agents in-house.

🚨 Stop losing leads to slow follow-up. We fix that. Every new lead gets called within 60 seconds, every inbound call gets answered, and appointments get booked onto your calendar automatically. No fluff, no AI buzzwords. Just faster response, more booked appointments, and better ROI on your ad spend. Book a free 15-minute consultation here: https://cal.com/hsienjun.ong/growth-mapping

Call Sandwich is a certified Elite Retell AI partner — the highest tier in Retell's partner program. We specialize in building enterprise-grade voice AI integrations for complex telephony environments that standard agencies won't touch. Our team connects Retell to legacy and modern stacks alike — ViciDial, Asterisk, FreeSWITCH, NICE inContact, Avaya, Talkdesk, Genesys, and more — handling everything from SIP trunk configuration to full white-label AI platform development. Whether you need outbound AI sales agents, enterprise inbound routing, AI + human handoff, or a fully white-labeled Retell platform, Call Sandwich delivers production-ready, multi-tenant deployments built to scale.

Legacy AI is a custom development Voice AI agency specialising in building chat and voice AI agents. As a team of 8 talented AI Engineers, we've partnered with 52+ businesses across solar, restaurants, travel, hospitality, insurance, real estate/property management and other service industries, helping them eliminate operational bottlenecks, eliminate missed clients from missed calls, and recover lost revenue. Our clients include some of the fastest-growing brands in their categories, including a $250 Million Restaurant Franchise over 200 Locations in North America, to one of the world's largest travel agency. We truly believe in our ability to be your AI and Software Development Partner.

We are experts in AI Voice Agents for businesses in every sector. Tool and system integration is where our team really shines. From simple calendar booking systems, to complex inventory and tracking system integration, we handle it all with our team of dedicated AI Engineers and Software Developers. Our inbound AI provides round-the-clock customer support with consistent, reliable responses. On the outbound side, we automate lead qualification by instantly following up on ad inquiries and booking appointments directly into your calendar. We also specialize in database reactivation, re-engaging cold or dormant leads to recover lost revenue.