Senior Software Engineer II, Messaging Platform

Requirements

• Has 7+ years of backend engineering experience working on highly available, scalable systems.
• Is comfortable working with technologies like Java, Kotlin, MySQL, Kafka, HBase, and Kubernetes (experience with specific stacks is less important than strong fundamentals).
• Understands distributed systems, networked services, and high-throughput data flows.
• Enjoys solving complex reliability, throughput, and performance challenges.
• Communicates clearly and collaborates effectively with engineers, PMs, designers, and domain experts.
• Builds with empathy for the end user—and for the downstream teams who build on our infrastructure.
• Thrives in an environment where curiosity, pragmatism, and resourcefulness drive impact.

What You'll Be Doing

• Design, build, and maintain high-scale backend services that support email sending, routing, and deliverability across the HubSpot platform.
• Contribute to the development of HubSpot’s in-house MTA and systems managing global IP networks.
• Enhance reliability, observability, and performance within a mission-critical messaging pipeline.
• Collaborate closely with infrastructure teams, product managers, and deliverability experts to ensure safe, consistent, high-quality message delivery.
• Lead design discussions, participate in architectural decisions, and help shape long-term technical strategy.
• Write clean, testable, and maintainable code that follows best practices for distributed systems and network-intensive workloads.
• Engage in code reviews, mentor fellow engineers, and foster a culture of learning and operational excellence.

Perks and Benefits

• Email is one of the most critical and widely used communication channels at HubSpot, and the infrastructure supporting it directly impacts how our customers do business.
• The systems you build and maintain in this role will power the sending of billions of messages each month, enabling companies of all sizes to reach their audiences, nurture relationships, and drive revenue.
• Your work will influence deliverability, latency, reliability, and trust—factors that determine whether our customers’ messages land in inboxes or disappear into the void.
• By strengthening HubSpot’s email infrastructure, you help safeguard our global sending reputation and enable us to grow safely as our customer base and message volume expand.
• The features you develop will lay a foundation not only for email but also for future messaging channels and intelligent routing options across the platform.
• This role influences how effective, reliable, and powerful HubSpot’s messaging experience is for millions of users worldwide.