Backend Engineer, MTA

Role Overview

This opening is for a Backend Engineer, MTA position based in Ireland, with full remote work flexibility. The role involves creating and managing the backend systems vital for processing extremely high volumes of email deliveries. The engineer will be responsible for key components such as SMTP delivery, routing, retry mechanisms, throttling controls, and ensuring the overall resilience and effectiveness of the email sending infrastructure.

Key Responsibilities

• Develop, maintain, and optimize email transport and delivery backend components.
• Implement solutions for SMTP operations including delivery, routing, retry strategies, and controlling delivery flow.
• Create throttling systems managing limits across various dimensions like domain, provider, customer, and IP.
• Support infrastructure for managing IP pools (shared and dedicated), IP warmup procedures, and routes influenced by sender reputation.
• Enhance handling and classification of email bounces, deferrals, transient and hard failures to improve delivery outcomes.
• Build internal tools to facilitate easier diagnosis of email delivery issues across multiple parameters.
• Design systems that improve safety, observability, reliability, and operational efficiency in email sending.
• Translate sender reputation strategies into enforceable backend controls and mechanisms.
• Work in close collaboration with Trust & Safety as well as Core Sending teams to safeguard the network from abuse and maintain integrity.
• Participate in incident analysis and resolution processes for issues linked to sending and delivery.
• Engage in on-call rotations to support critical service availability and reliability.

Candidate Qualifications

• Proven experience in backend software engineering roles.
• Background working with large-scale email systems, messaging platforms, notification services, or similar high-throughput communication infrastructures.
• Strong knowledge of core distributed system concepts such as queues, worker models, retries, idempotency, rate limiting, and backpressure mechanisms.
• Experience with or enthusiasm to deeply understand SMTP protocols, message transfer agents, DNS, bounce management, and mailbox provider behaviors.
• Commitment to maintaining and improving system reliability, observability, and operational processes to minimize incident impact.
• Strong ownership mentality coupled with collaborative spirit and preference for designing straightforward, maintainable solutions.
• Hands-on experience in building, deploying, and sustaining applications under heavy workloads.
• Familiarity with email best practices or a willingness to build expertise in email-specific technologies.
• Proficiency or experience with TypeScript and/or Go programming languages is highly desirable.
• Ability to thrive in a fully remote, distributed team environment with flexible working hours.

Benefits and Working Environment

• Fully remote employment with flexible scheduling.
• Competitive salary range between 150000 and 170000 USD annually, based on experience.
• High autonomy to identify challenges, develop solutions, and implement improvements independently.
• Exposure to a contemporary technology stack including TypeScript, AWS, Go, PostgreSQL, and Datadog.
• Collaborative culture characterized by honesty and low ego.
• Significant ownership of core infrastructure and technical decisions.
• Opportunities to attend remote team off-sites, industry conferences, meetups, and other professional events.
• Chance to contribute to large-scale email infrastructure supporting millions of users worldwide.

Additional Information

The application process is managed by a partner company responsible for all recruitment steps and communications. Applications are evaluated using AI-assisted matching to ensure speedy and impartial selection aligned with core requirements. Final hiring decisions include human oversight. Occasional travel may be required for team gatherings and professional events.