Senior Full-Stack Developer Cold Email Sequencer (India)

Senior Full-Stack Engineer (Email Automation Platform) Remote | Full-Time Location: Remote Employment Type: Full-Time Experience: 5+ Years Build the Future of Cold Email Infrastructure A t Mailin. ai, we're building the next generation of email infrastructure and outbound automation. Our platform powers high-volume outbound campaigns for businesses that rely on reliable, scalable email delivery. We're looking for a Senior Full-Stack Engineer who can take ownership of building a production-grade email sequencing platform comparable to Instantly, Smartlead, Apollo, or Lemlistdesigned for scale, reliability, and exceptional user experience. This isn't a maintenance role. You'll architect, build, and ship core platform capabilities that send millions of emails while maintaining industry-leading deliverability. What You'll Build You'll own major parts of our outbound automation platform, including: Email Campaign Engine - Multi-step email sequences - Campaign scheduling and business hours - Smart follow-up automation - Conditional branching based on opens, replies, clicks, bounces, and custom events - Campaign throttling and rate limiting - Queue-based email processing Lead & Contact Management - CSV and API imports - Lead segmentation and tagging - Custom fields and dynamic variables - Duplicate detection - Personalization engine Sending Infrastructure - SMTP, Gmail OAuth, Microsoft 365 OAuth - Multiple mailbox management - Automatic mailbox rotation - Domain-aware sending - Queue management and retry systems - High-volume email delivery optimization Unified Inbox - Conversation threading - Reply detection - Team collaboration - Search, filters, and labels - Inbox workflow management Deliverability Platform - Mailbox health monitoring - Bounce tracking - Reputation analytics - Domain health dashboards - Warm-up integrations - Sending optimization AI & Personalization - AI-powered email generation - Subject line generation - Energetic personalization - Tem .