Senior Software Engineer

EasyPost is looking for a hands-on Senior Software Engineer to help build and operate our secure document-delivery platform.

Our customers use EasyPost to send invoices and business documents through channels such as Peppol e-invoicing, Belgian eBox, electronic registered delivery, e-signing, email and print. Behind this experience is a large event-driven AWS platform that processes sensitive documents, integrates with external providers and coordinates long-running delivery workflows.

You will take ownership of features from technical design through production. This role focuses on backend and cloud engineering. You will work closely with our team lead, product management and other engineers to design reliable, secure and maintainable solutions.

As one of the team’s senior engineers, you will also help shape the platform’s architecture, evaluate technical trade-offs and turn business requirements into practical technical designs.

What you will do

• Design and develop TypeScript services, AWS Lambda functions and NestJS APIs.

• Build and maintain serverless infrastructure using AWS CDK.

• Translate business requirements into clear technical designs together with the team lead.

• Contribute to architectural decisions and document their context, trade-offs and consequences.

• Create resilient event-driven workflows that handle retries, duplicate events, timeouts, concurrency and partial failures.

• Integrate with external e-invoicing, e-delivery and e-signing providers through APIs and webhooks.

• Work with AWS services such as Lambda, DynamoDB, EventBridge, SQS, Step Functions, API Gateway, S3 and CloudWatch.

• Apply security practices including encryption, least-privilege access, audit logging and safe handling of sensitive data.

• Write unit, integration and end-to-end tests using Jest.

• Monitor production systems and investigate issues across application code, AWS infrastructure and external integrations.

• Review code, mentor colleagues and raise engineering standards across the team.

• Improve our development, CI/CD and deployment processes.

• Collaborate with frontend engineers to ensure backend services and APIs support complete, reliable user journeys.