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.
• The systems you build and maintain in this role will power the sending of billions of messages each month.
• 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.