Software Engineer (L3) Email

Hiring and how we work

See yourself at Twilio

Join the team as Twilio’s next Software Engineer, (L3) Email

This position is a critical engineering role within Twilio SendGrid, requiring a hands-on engineer capable of developing, deploying, and managing highly available, massive-scale distributed systems.

Our systems regularly process more than 12 billion emails during peak events like Black Friday, and our throughput requirements continue to scale rapidly. As an L3 engineer, you will act as a key driver of execution within our core services. You will be heavily involved in modernizing our backend systems, optimizing our extensive Go-based microservices, and contributing to the design and reliability of our dual-cloud infrastructure span across Amazon Web Services (AWS) and Microsoft Azure.

In this role, you’ll:

• WEAR THE CUSTOMER’S SHOES: Architect and ship reliable, high-velocity features that handle critical traffic with low end-to-end latency. Partner closely with product management and technical leadership to break down complex system requirements into manageable, iterative milestones.
• BE AN OWNER (CODE QUALITY): Drive rigorous code reviews and push for maintainable patterns in our Go codebase, ensuring high testing standards (unit, integration, and component testing) are executed across the team.
• BE AN OWNER (INFRASTRUCTURE & OBSERVABILITY): Manage and enhance cloud configurations across AWS and Azure environments utilizing Infrastructure as Code (Terraform). Ensure deep observability coverage by standardizing metrics, alerts, and distributed tracing across core data pipelines.
• CHAMPION ENGINEERING HEALTH: Advocate for a clean architectural foundation. Proactively identify technical debt, system bottlenecks, and single points of failure (SPOF), balancing feature delivery with critical platform refactoring.
• MENTOR AND LEAD: Foster a collaborative environment by mentoring junior engineers, leading technical sprint planning, and sharing expertise across distributed engineering nodes.
• Experience: 4+ years of professional software engineering experience building and operating resilient backend services at scale.
• Modern Development Workflow: Practical experience leveraging AI-assisted development tools (such as Claude Code) to accelerate code generation, automate testing, and streamline debugging workflows.
• Language Proficiency: Strong, hands-on production experience writing clean, idiomatic, and highly concurrent Go (Golang), Java or Python .
• Cloud Infrastructure: Solid experience deploying and managing production workloads in cloud environments—ideally with deep exposure to AWS core services (such as EC2, S3, Aurora, or DynamoDB) AND Microsoft Azure equivalents (such as Virtual Machines, Blob Storage, Azure SQL, or Cosmos DB).
• Infrastructure as Code: Proficiency with Terraform for provision-level automation and maintaining environment parity.
• Distributed Systems: Strong theoretical and practical understanding of distributed datastores, caching layers, and asynchronous event streaming (e.g., Kafka or similar queuing ecosystems).
• Systems Mindset: Strong foundational background in computer science fundamentals, data structures, and building self-healing cloud architectures.
• Prior experience managing high-throughput applications running inside containerized infrastructure ( Docker, Kubernetes ).
• Familiarity with database migration pathways (e.g., transitioning traditional on-prem/relational datastores to managed instances like AWS Aurora ).
• Experience implementing OpenTelemetry or distributed tracing systems across decoupled microservice platforms.
• Direct experience handling constraints related to network topology, proxy layers, or mail transfer agent (MTA) protocols.

…