MarTech Integrations Developer (GHL + Smartlead + Twilio + Retell — API-Level using Replit

$500 a month as I raise Capital. Replit cost and other marketing costs will be mine. Your job is to make sure you have strong understanding of Replit, Smartlead.ai, Twilio API, Sendgrid API, Retell API. Read the job description please. About us FullHouse (tryfullhouse.com) is an AI-powered marketing platform in Southwest Florida, USA — social media, reviews, websites, email, SMS, and an AI phone receptionist for small businesses. The platform is built in Replit; you'll get access and ship real integration code that runs for real businesses within days. Read this before applying — the four non-negotiables This role requires hands-on API knowledge of ALL FOUR of these. Not "familiar with." Not "watched tutorials." You have built against these APIs or administered them deeply, and our test round will prove it. If you're missing one, do not apply — we will find out at the paid test. GoHighLevel — sub-accounts/locations, contacts & workflows, webhooks, OAuth/API access, snapshots, LC Phone/Email mechanics Smartlead — campaigns, lead upload, client sub-accounts, warmup behavior, reply/webhook handling, deliverability discipline Twilio — Messages API, Messaging Services, inbound webhooks + signature validation, status callbacks, number provisioning, A2P 10DLC registration flow (brand → campaign → gate) Retell AI — agent configuration, outbound call creation with dynamic variables, custom tools / function calling (your webhook answering mid-call), post-call analysis webhooks The role Build and maintain our vendor integrations in Replit (JavaScript/TypeScript + REST/webhooks): dispatch code, webhook receivers, retry/dedupe logic, status syncing Implement features from our written specs (we write detailed requirements with acceptance tests — you code to them and PASTE RAW TEST OUTPUT, never just "done") Debug production issues across the four vendors: read logs, trace a message from trigger → API call → webhook → database Respect the platform's hard rules: compliance gates (opt-outs, quiet hours, registration status) are never bypassed; no hardcoded values; fail loud, never silently Keep us sharp on what these platforms ship (you'll maintain test accounts and flag new capabilities monthly) Also required Solid JavaScript/TypeScript; comfortable in Replit; Git basics Webhook craft: signature verification, idempotent handling (dedupe on event IDs), returning 2xx fast and queueing heavy work You read API docs for fun and answer questions with doc links, not vibes Good written English; US Eastern overlap for one weekly call