Full Stack Developer

Oasys International, LLC; Washington (District of Columbia); On-site; USD 120,000 - 180,000; Full time

Job summary

Oasys International LLC is seeking an experienced Full Stack Developer to guide a development team in learning new tools, implementing system improvements, and mentoring teammates. The role focuses on designing, building, and modernizing secure, scalable applications hosted on AWS, with responsibilities spanning architecture, cloud infra, and DevOps automation.

The candidate will work in an Agile environment with 2‑week sprints, Jira/Confluence, GitHub for source, and CI/CD pipelines.

Qualifications

• Bachelor’s degree or equivalent in engineering, CS, or related technical field.
• Minimum five years building and integrating complex full‑stack apps.
• Proficient in HTML, JavaScript, CSS and modern JS frameworks.
• Experience with RESTful and GraphQL APIs and relational/NoSQL databases.
• Experience implementing CI/CD pipelines with common tools.

Responsibilities

• Evaluate platforms and architectures; specify hardware for dev/test/prod.
• Research and apply advances to mission-critical systems.
• Develop and maintain software architecture; write guidelines and train staff.
• Perform code reviews; diagnose and fix issues.
• Write, test, deploy, and document software for new and existing systems.
• Collaborate on multiple applications; modify and troubleshoot as needed.
• Translate requirements into scalable architectures and data models.
• Configure apps/servers with security best practices.
• Design and implement RESTful APIs; ensure secure integration across services.
• Contribute to service decomposition, API gateways, queues, and distributed systems.
• Monitor performance, scalability, and security; optimize across environments.
• Lead architecture reviews; evolve monoliths to microservices/hybrid models.

Skills

Containerization

Microservices

RESTful APIs

Cloud (AWS)

CI/CD pipelines

IaC (Terraform, CloudFormation)

Git/GitHub

Web technologies (HTML/JS/CSS)

Education

Bachelor's degree in Engineering/CS/related field

5+ years full-stack development

Tools

GitHub Actions

GitLab CI

Jenkins

Terraform

AWS CloudFormation

Docker

Kubernetes

PostgreSQL

Job description

Who We Are:

Oasys International LLC (Oasys) is a growing federal government contractor delivering innovative technology, engineering, and professional services in support of critical missions across the civilian, defense, and homeland security communities. Our continued growth and commitment to excellence have earned Oasys recognition on the Inc. 5000 list of America's fastest-growing private companies for five consecutive years and as a Best Place to Work in Virginia for the past two years.

At Oasys, our people are at the heart of everything we do. Our team of talented technologists, engineers, consultants, and subject-matter experts works alongside our federal customers to solve complex challenges, modernize critical systems, and make a meaningful impact on the missions we support.

What makes Oasys different is the experience we strive to create for our employees. We offer the opportunity to do meaningful work while being part of a collaborative, people-focused organization where your ideas, expertise, and contributions are valued. We believe great people do their best work when they have opportunities to grow, are recognized for what they bring to the team, and have the flexibility and support needed to build a rewarding career.

Whether you are looking to deepen your technical expertise, take on new challenges, or grow into your next leadership opportunity, Oasys is a place where you can build your career while contributing to missions that matter.

Join Team Oasys and bring your talent to a company where your work is valued, your growth is supported, and your impact matters.

Position Summary:

Oasys is searching for an experienced Full Stack Developer who will guide a development team in learning new tools and techniques, identifying and implementing system improvements, and mentoring teammates.

The full-stack developer will design, build, and modernize secure, scalable, mission-critical applications hosted on AWS (Amazon Web Services), with responsibilities spanning application architecture, cloud infrastructure, and DevOps automation. The team uses Agile methodology and operates on 2-week sprints, tracked in Jira with documentation in Confluence. We use GitHub for our source code repository, and we automate our CI/CD pipelines there as well. The entire infrastructure is written and managed as code, and we promote cloud and open-source technologies.

We are looking for a full-stack developer with experience in both monolithic and modern application architectures. Preferably, the candidate should have experience transitioning between monolithic and modern architectures, depending on what best fits the project. Our current suite of applications includes/combines Python, Django, Rails, React, TypeScript, Docker, Postgres, PostGIS, Snowflake, and more. If you are enthusiastic about being in a stack-agnostic environment and focusing on understanding the underlying core concepts and principles that drive modern application and infrastructure development, improvement, and maintenance, we would like to hear from you!

Primary Responsibilities:

• Evaluate and recommend software development platforms and architectures, as well as the hardware requirements for the support of development, testing, quality assurance, and production environments.
• Conduct applied research in current and emerging computer technology to integrate appropriate new technological advances into the mission.
• Develop and maintain software development architecture and make recommendations for improvement. Establish and document software development guidelines and coding standards and conduct training sessions as needed.
• Conduct code review and diagnose technical issues reported.
• Write program code, compiles, debugs, tests, deploys, documents, and implement programs for new and existing systems e.g.
  • COTS - Commercial Off-The-Shelf
  • GOTS - Government Off-The-Shelf
  • OSS - Operations Support System
  • Custom-developed
• Serve as a member of a team of programmers responsible for developing, implementing, and maintaining several diverse applications. Modify existing applications when required and resolve technical issues as needed.
• Translate business and system requirements into scalable technical architectures and data models.
• Provide input for configuring the applications and servers on which application programs run to ensure that information security/information assurance principles related to the mission are adequately addressed.
• Design and implement RESTful APIs and ensure integration across frontend, backend, and external services with strong authentication and authorization models.
• Contribute to decisions on service decomposition, API gateway usage, message queues, and distributed systems design.
• Monitor and optimize application performance, scalability, and security across environments using tools like CloudWatch, Prometheus, Grafana, or similar.
• Participate in and lead architecture reviews to evolve monoliths into microservices or hybrid models when appropriate.
• All other duties as assigned by management.

Skills and Qualifications:

• An ability to understand business requirements and their implications across a project's technical landscape.
• Ability to walk concepts forward and backward with the client and team - using your informed technical experience to negotiate/guide functional requirements from the front to the back end.
• Understanding of containerization, container orchestration, microservices, and API (application programming interfaces) management.
• Demonstrate sharp, analytical, problem-solving, and decision-making skills. Passion and a continuous-improvement mindset
• Self-motivated
• Demonstrate skills and experience in presenting analytical results verbally and in writing.
• Must be proficient with common productivity software, including Microsoft Office (Word, Excel, PowerPoint, SharePoint, Visio, and Outlook).
• Must have excellent verbal and written communication skills and be highly organized with attention to detail. Must be comfortable and capable of interacting with Government, contractor, and executive leadership.
• Deep understanding of HTTP, WebSocket, load balancing, reverse proxies, and API security practices (OAuth2, JWT, CORS).
• Proficiency in Infrastructure as Code (IaC) using tools such as Terraform or AWS CloudFormation.
• Familiarity with networking fundamentals, including VPCs, subnets, security groups, and service discovery.

Required Education and Experience:

• Bachelor's degree in Engineering, Computer Science, or another related analytical, scientific, or technical discipline; additional experience in lieu of a degree.
• Minimum of five (5) years of demonstrated experience building and integrating complex full-stack applications using modern front-end frameworks, RESTful and GraphQL APIs, relational and NoSQL databases, and containerized backends.
• Proven knowledge and practical application of HTML, JavaScript, CSS, or any other relevant web development experience.
• Experience with modern JavaScript frameworks and libraries such as React, Redux, Vue, Ember, or Angular and knowledge of when to use them.
• Experience with programming and software development, including analysis, design, development, implementation, testing, maintenance, quality assurance, troubleshooting, debugging, and/or upgrading software systems.
• Experience implementing CI/CD pipelines with tools like GitHub Actions, GitLab CI, Jenkins, or similar.

Preferred Qualifications:

• Expertise with git as a version control system and team collaboration with git.
• Experience with debugging front-end and back-end issues.
• Experience with pair programming and Extreme Programming (XP).
• Experience with any content management systems.
• Experience working with PaaS products such as Salesforce, ServiceNow, and Appian.
• Familiarity with OOP (Object Oriented Programming) concepts.
• A passion to contribute to the full stack - the front-end, back-end, and anything in-between (middleware or otherwise).
• Computer Science fundamentals in object-oriented (OO) design, data structure, and algorithm design.
• Experience with event-driven systems (e.g., using Kafka, SQS/SNS, or RabbitMQ).
• Experience with serverless architectures (e.g., AWS Lambda, Step Functions).
• Experience with API documentation tools such as Swagger/OpenAPI.
• Strong background in test-driven development (TDD) and quality assurance across the stack.
• Experience in building reusable web components.
• Familiarity with JavaScript build tools such as NPM/yarn, webpack, and Babel.
• Experience with Node.js and Java-based web applications.
• Experience with unit testing, regression testing, and user testing.
• Experience with a federal agency as a contractor or federal employee.

Security Clearance Requirements:

• Must be a U.S. Citizen
• Must be able to obtain a Public Trust

Work Location:

• Washington, DC

Oasys is proud to be an equal opportunity employer for all protected groups, including protected veterans and individuals with disabilities.