Job Summary: We are seeking a Senior Backend Developer with experience in Firebase, Cloud Functions, and AI APIs to build the core logic of a SaaS product. Key Highlights: 1. Opportunity to work with modern technologies (Serverless + AI). 2. Open, collaborative culture focused on growth. 3. Professional development and participation in product decisions. We are looking for a **Senior Backend Developer** with solid experience in **Firebase**, **Cloud Functions**, and consuming **Artificial Intelligence (Google Gemini)** APIs. You will build the core logic of a SaaS product, payment integrations, secure endpoints, and intelligent workflows powered by AI. If you enjoy working with serverless architecture, optimizing Firestore, creating robust security rules, and solving complex challenges, this position is for you. Responsibilities: * Design and develop serverless functions (Node.js / TypeScript) on Firebase. * Model efficient and scalable data structures in Firestore. * Create and maintain advanced security rules. * Implement integrations with **Stripe** or **MercadoPago** (subscriptions, webhooks, billing). * Consume **Google Gemini / Vertex AI** APIs for intelligent features. * Create and document secure REST endpoints. * Collaborate with frontend and product teams to define technical solutions. * Participate in architecture decisions oriented toward performance and cost-efficiency. Requirements: * Backend development experience. * Proficiency in Firebase (Cloud Functions, Firestore, Security Rules). * Strong expertise in Node.js / TypeScript. * Experience with AI APIs (Google Gemini, OpenAI, etc.). * Payment gateway integration: Stripe or MercadoPago. * Experience building SaaS systems (roles, plans, subscriptions). * Good practices in version control, security, and documentation. We Offer: * Competitive salary commensurate with experience. * Flexible working hours. * Opportunity to work with modern technologies (Serverless + AI). * Open, collaborative culture focused on growth. * Professional development and participation in product decisions. If you are interested, please apply through this channel and we will contact you shortly. Employment Type: Full-time, Indefinite-term Salary: $14,000.00 – $16,000.00 per month Work Location: On-site