Senior Application Developer (AWS/Python) onsite

System One; Washington (District of Columbia); On-site; USD 120,000 - 180,000; Full time

Job summary

System One in Washington, DC is seeking a Senior Application Developer (AWS/Python) for a 100% onsite role. U.S. citizenship is required and the candidate must be able to obtain Public Trust clearance.

You will develop Python-based microservices, use AWS CDK for infrastructure, design RESTful APIs, and manage CI/CD pipelines. The position emphasizes code quality, tests, logging, and collaboration with stakeholders to translate business needs into scalable technical solutions.

Qualifications

• BS in Computer Science/IT or equivalent work experience.
• 7+ years software development experience with SDLC and Agile methodologies.
• Production-grade Python development with modern frameworks and testing.

Responsibilities

• Develop and maintain Python-based microservices and AWS infrastructure using CDK
• Model complex business workflows with AWS Step Functions
• Build containerized applications with RESTful APIs
• Implement comprehensive logging, monitoring, and audit trails (CloudWatch, CloudTrail)
• Conduct code reviews focusing on maintainability and performance
• Write unit tests and integration tests; perform code remediation
• Collaborate with stakeholders to translate business requirements into technical solutions

Skills

Python

AWS CDK

CI/CD

API Design

Git workflows

Education

BS in Computer Science/IT

Tools

Terraform

Docker

GitLab

Job description

Senior Application Developer (AWS/Python)

Washington, DC – 100% Onsite

Per Federal contract U.S. citizenship is required

Must be able to obtain Public Trust clearance

W2 or C2C

Application Deadline: 9/10

Core Responsibilities:

Development & Infrastructure:

• Develop and maintain Python-based microservices and AWS infrastructure using CDK
• Model complex business workflows with AWS Step Functions
• Build containerized applications with RESTful APIs
• Implement comprehensive logging, monitoring, and audit trails (CloudWatch, CloudTrail)

Quality & Collaboration:

• Conduct code reviews focused on maintainability, performance, and best practices
• Write unit tests and integration tests; perform code remediation
• Contribute to architecture decisions and maintain technical documentation
• Collaborate with stakeholders to translate business requirements into technical solutions

Required Qualifications:

Core Technical Skills:

• Python: Production-grade development with modern frameworks and testing libraries
• AWS CDK: Infrastructure-as-code for multi‑environment deployments
• CI/CD: Hands‑on pipeline creation and management for cloud applications
• API Design: RESTful service design, versioning, and error handling
• Version Control: Git workflows, branching strategies, merge request reviews

Technical Stack:

Primary (daily use expected):

• Python 3.9+, AWS Lambda, Step Functions
• IaC: CDK, Terraform experience
• DynamoDB, S3, API Gateway, CloudWatch, CloudTrail
• Docker, Git/GitLab

Secondary (nice to have):

• Frontend: Angular or React (TypeScript)
• AWS Services: SNS/SQS, Athena, Glue, Load Balancers

Productivity Tools (Plus):

• AI-Assisted Development
• Experience using AI coding assistants such as Claude Code for:
  • Code review and optimization suggestions
  • Documentation generation
  • Debugging and troubleshooting
  • Test case development
• Ability to critically evaluate and adapt AI-generated code

Education & Experience:

• BS in Computer Science/IT or equivalent work experience
• 7+ years software development experience with SDLC and Agile methodologies

System One, and its subsidiaries including Joulé and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. System One not only serves as a valued partner for our clients, but we offer eligible employees health and welfare benefits coverage options including medical, dental, vision, spending accounts, life insurance, voluntary plans, as well as participation in a 401(k) plan.

System One is an Equal Opportunity Employer.

All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, age, national origin, disability, family care or medical leave status, genetic information, veteran status, marital status, or any other characteristic protected by applicable federal, state, or local law.

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