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 .