Sr. Software Engineer

ShipServ Limited; Michigan; Remote; USD 24,000 - 30,000; Full time

Job summary

ShipServ Limited is seeking an Email Infrastructure Engineer to optimize and build systems processing millions of emails. Join a rapidly growing profitable company and help shape the future of email deliverability services. Ideal candidates have expertise in SMTP protocols, email authentication, and back-end technologies.

Qualifications

• 5+ years software engineering experience with expertise in email infrastructure.
• Experience in high-volume email systems and distributed infrastructure.
• Strong understanding of anti-spam technologies and email authentication protocols.

Responsibilities

• Enhance SendGrid-like API infrastructure for cold outreach and sales email.
• Work on the AI-powered spam filter to improve email deliverability.
• Optimize and scale dedicated IP systems.

Skills

Email infrastructure expertise

SMTP protocols

Mail server management

Email deliverability

Reputation management

DNS records management

API development

Code quality practices

Job description

Mission Inbox | Remote | $24,000 - $30,000 annually

We're Mission Inbox, the infrastructure company that's rewriting the rules of business email. Like how AWS became the backbone for modern applications, we're building the dedicated backbone for revenue-generating email - because email was never the problem, who controlled it was.

The Role

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.

What You'll Build

OBM Engine: Enhance our SendGrid-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

Our Values in Action

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

Technical Requirements

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

Who Should NOT Apply

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

Why Mission Inbox

Join a profitable, bootstrapped company that grew 393% in just over a year. You'll work alongside email deliverability experts who understand that fixing email infrastructure requires both deep technical knowledge and business acumen. This is infrastructure work that directly translates to customer revenue - when our systems perform better, our customers literally make more money.

We're not just building software; we're building the modern backbone of outbound communication. If you're ready to own a critical piece of infrastructure that processes millions of revenue-generating emails, let's talk.

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Our Hiring Journey Because building email infrastructure that changes it all requires the right team:

Step 1: Technical Deep Dive Assessment

Step 3: Technical Leadership Discussion Y