Sr Software Engineer

You'll be working directly on the systems that process 15M+ emails monthly for 50+ B2B customers. This isn't about building another email client - you'll be engineering the foundational layer that makes sales emails actually reach inboxes. Think of yourself as both a plumber and an architect: ensuring robust flow while designing systems that scale.

• OBM Engine:
  Enhance our Send Grid-like API infrastructure designed specifically for cold outreach and sales email
• MI Shield Integration:
  Work with our AI-powered spam filter trained on 41M+ sales emails to block risky emails before they're sent
• Dedicated Infrastructure:
  Optimize and scale our dedicated IP systems that prevent the "shared IP death spiral" plaguing competitors
• MI-Workspace Components:
  Contribute to our evolving ecosystem including DNS management, CRM integrations, and email clients

• Own It:
  Take full accountability for email deliverability systems that directly impact customer revenue
• Build Solutions:
  Create infrastructure solutions that don't exist elsewhere in the market
• Quality as a Signature:
  Write code that handles millions of emails with zero tolerance for failure. We encourage AI-assisted development to accelerate your expertise, but you own every line of code that goes into production
• Customer ROI in Mind:
  Every line of code should improve customer email performance and delivery rates

• 5+ years software engineering experience with proven expertise in email infrastructure, SMTP protocols, and mail server management
• Deep understanding of email deliverability, reputation management, DNS records (SPF, DKIM, DMARC), and ISP relationships
• Experience with high-volume email systems, queue management, and distributed infrastructure
• Proficiency in backend technologies and API development (our stack includes modern cloud infrastructure)
• Understanding of anti-spam technologies, reputation monitoring, and email authentication protocols
• Strong code quality practices with personal accountability for production systems
• Bonus:
  Proficiency with Claude Code and intelligent AI-assisted development - we encourage using AI to accelerate your expertise, not replace your technical judgment

• Developers looking for typical CRUD app work or frontend-focused roles
• Those who view email as "just another messaging protocol" rather than a complex infrastructure challenge
• Engineers who rely on AI-generated code without understanding the underlying logic or maintaining code quality standards
• "Copy-paste developers" who use AI as a crutch rather than a tool to amplify their existing expertise
• Anyone uncomfortable with the regulatory and compliance aspects of email infrastructure
• Engineers uncomfortable with individual accountability for code that handles millions of revenue-generating emails
• Those seeking a traditional 9-5 with minimal ownership or accountability
• Developers who prefer working in isolation rather than directly impacting customer outcomes

As spam filters tighten, 52% of business emails go unseen, crippling sales and collections for B2B companies. Mission Inbox solves this by giving companies full control of their email infrastructure—without needing to manage complex servers or rely on Gmail hacks.