Senior software-ingenieur

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.

Your role

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.

• Senior-level experience designing, building and operating production software.
• Strong TypeScript and Node.js skills.
• Hands-on experience with AWS serverless or event-driven systems.
• Experience defining infrastructure as code, preferably with AWS CDK.
• The ability to design systems, evaluate trade-offs and communicate technical decisions clearly.
• A good understanding of distributed-system concepts such as idempotency, eventual consistency, retries, dead-letter queues and event ordering.
• Experience building REST APIs and third-party integrations.
• Experience with NoSQL data modelling, preferably DynamoDB.
• A security-conscious approach to personal data, credentials, permissions and encryption.
• Experience with automated testing, code review and CI/CD.
• The ability to troubleshoot complex production issues.
• Clear English communication and the ability to work effectively with engineering and product stakeholders.
• A strong sense of ownership-from the first design decision to how the feature behaves in production.
• The willingness to mentor colleagues and help the team make sound technical decisions.

Useful additional experience

• NestJS.
• React or Ant Design.
• Nx monorepositories.
• OpenSearch or Elasticsearch.
• Bitbucket Pipelines.
• Multi-account AWS environments.
• PDF, Word, XML or UBL document processing.
• Peppol, e-invoicing, e-signatures or registered electronic delivery.
• Modernising a large existing platform while keeping it operational.
• Writing technical designs or Architecture Decision Records.

You do not need prior experience with our specific document-delivery channels. We care more about your ability to understand complex systems and learn new domains quickly.

What you can expect

• Meaningful technical and architectural ownership.
• Close collaboration with the team lead and product management.
• Challenging distributed-system and integration problems.
• The opportunity to influence architecture and engineering practices.
• A product where security, reliability and code quality genuinely matter.
• A collaborative environment in which senior engineers remain close to the code.