Senior Backend Engineer – Java/AWS

ZipStaff•Washington, DC

7h•Onsite

About The Position

ZipStaff is hiring a Senior Backend Engineer for a national passenger transportation organization to build and support cloud-native integrations and transaction-processing services behind critical operational systems. The role involves hands-on ownership of resilient, multi-region AWS architectures, event-driven pipelines, and automated CI/CD workflows, with a focus on high reliability, rapid disaster recovery, and seamless B2B data exchange. The position is an on-site W2 contract role in Washington, DC.

Requirements

7+ years of professional backend software engineering experience on distributed, high-availability production systems.
Advanced hands-on proficiency in Java 17+, Spring Boot, and Python.
Extensive experience with AWS services including ECS/Fargate, EventBridge, SQS, SNS, Lambda, S3, and CloudWatch.
Strong PostgreSQL/Amazon Aurora PostgreSQL skills, including schema design, query optimization, and tuning.
Experience managing automated deployments with Jenkins, GitHub Actions, AWS CodePipeline, and CloudFormation.
Proficiency with automated unit and integration testing frameworks, including JUnit and Mockito.
Bachelor's degree in Computer Science, Engineering, or a related field, or equivalent experience.
Ability to work on-site in Washington, DC.

Nice To Haves

Active AWS certification, such as Solutions Architect, Developer Associate, or Cloud Practitioner.
Experience with EDI, B2B messaging integrations, or high-volume transportation/logistics systems.
Based within or easily accessible to the Northeast Corridor for periodic on-site planning sessions.

Responsibilities

Design, build, deploy, and maintain scalable microservices, RESTful APIs, and event-driven architectures using Java 17+, Spring Boot, Python, and AWS integration services.
Architect fault-tolerant, high-availability solutions across multiple AWS Availability Zones and Regions, including failover testing and efforts to reduce MTTR.
Investigate complex production incidents, perform root cause analysis, and implement observability with Amazon CloudWatch.
Build and optimize CI/CD pipelines using GitHub Actions, Jenkins, AWS CodePipeline, and CloudFormation infrastructure-as-code.
Implement relational data models, write complex queries, and tune performance on Amazon Aurora PostgreSQL.
Drive peer code reviews, champion automated testing standards using JUnit and Mockito, and mentor junior developers.