API Engineer, Mid-level with Security Clearance

Modus21, LLC.; St. Louis (MO); Hybrid; USD 110,000 - 160,000; Full time

Job summary

Modus21, LLC. is seeking a Mid-level API Engineer to design, deploy, and optimize robust API platforms for secure data exchange across DoD environments.

You will implement authentication, rate limiting, and monitoring while integrating with CI/CD pipelines and backend systems. Collaboration with clients and teams is essential to deliver scalable, compliant solutions.

Qualifications

• 3+ years of backend or platform engineering experience including distributed systems and API design.
• 3+ years in software development using Java or Python; 2+ years with real-time, low-latency API platforms at scale.
• 1+ years DevOps with Docker, Helm, Kubernetes, and GitOps workflows.
• Experience with HTTP, gRPC, WebSockets, caching, load balancing, and API security.
• Experience with AWS, Azure, or GCP.
• Experience with Git and collaboration tools (Jenkins, JIRA, Confluence, Nexus, Bitbucket).
• Experience with SQL, Server-Side Development, Middleware, API Development, Spring stack.
• Experience with a message broker like Kafka or RabbitMQ.
• Security+ or DoD 8570 certification.

Responsibilities

• Design, deploy, and optimize robust API platforms for data exchange and integrations.
• Write secure server-side logic and integrate APIs with backend systems and databases.
• Implement authentication (OAuth, JWT), rate limiting, and monitoring.
• Build API validation, integration, and resiliency tests; integrate with CI/CD.
• Maintain detailed API documentation for developers.
• Explain technical considerations in meetings with internal clients.

Skills

Backend engineering

API design

Java

Python

DevOps

Docker

Kubernetes

Security

Cloud (AWS/Azure/GCP)

CI/CD

OAuth/JWT

WebSockets

gRPC

SQL

Education

HS Diploma or GED

Tools

Apigee

Gravitee

Kong

AWS API Gateway

Mulesoft

Docker

Kubernetes

Jenkins

JIRA

Confluence

Nexus

Bitbucket

Job description

Position Title: API Engineer, Mid-level

Location: HYBRID/Scott Airforce Base, IL/Or Remote

Status: Contingent Upon Award Modus21 is a Charleston, South Carolina based business and technology consulting firm specializing in solving complex business problems for global business and government clients. Our philosophy is simple - provide value to our clients through the ability to streamline, measure, and improve their business processes via business intelligence and business architecture. Our expertise has proven highly successful in helping organizations recognize greater value by aligning their strategy and objectives to technology and execution.

Scope of Work: U.S. Transportation Command (USTRANSCOM) is the single manager for global patient movement for the Department of War (DoW), responsible for synchronizing transportation and medical evacuation to provide life‑saving care to warfighters across the spectrum of military operations. TRAC2ES is a critical system for the DoW supporting global patient movement operations by integrating medical regulating, patient evacuation, and command and control decision support, ensuring efficient and secure patient movement across peace, war, and contingency scenarios. TRAC2ES handles sensitive data, including Personal Identifiable Information (PII) and Protected Health Information (PHI), and operates within both classified and unclassified environments. USTRANSCOM seeks innovative solutions to enhance, sustain, and modernize TRAC2ES. The solution must address challenges in scalability, performance, cybersecurity, interoperability, and operational efficiency while ensuring compliance with DoW standards. Additionally, the solution must include options for transitioning TRAC2ES functionality to a secure, user‑friendly mobile application to improve accessibility and operational efficiency in diverse operational environments. The solution must optimize TRAC2ES's capabilities to meet evolving mission requirements while ensuring compliance with DoW standards, including Zero Trust (ZT) principles.

Responsibilities:

• Designing, deploying, and optimizing robust API platforms for efficient data exchange, system integrations, and secure communication
• Write secure, efficient server‑side logic and integrate APIs with backend systems and databases.
• Implement authentication (OAuth, JWT), rate limiting, and monitoring to prevent bottlenecks and vulnerabilities.
• Build programmatic API validation, integration, and resiliency testing, often integrating with CI/CD pipelines.
• Maintain detailed documentation so developers can easily understand and consume the APIs.
• Explain technical considerations at related meetings, including those with internal clients

Requirements/Experience:

• HS Diploma or GED
• 3+ years of experience in backend or platform engineering, including distributed systems and API design
• 3+ years of experience in software development using Java or Python; 2+ years of experience with designing, deploying, and operating real‑time, low‑latency API platforms at scale such as Apigee, Gravitee, Kong, AWS API Gateway, or Mulesoft;
• 1+ years of experience with DevOps practices and technologies, including Docker, Helm, Kubernetes, and GitOps workflows;
• Experience with protocols, including HTTP, gRPC, or WebSockets, caching, load balancing, and API security;
• Experience with AWS, Azure, or GCP;
• Experience with Git and collaboration tools, including Jenkins, JIRA, Confluence, Nexus, or Bitbucket;
• Experience in gathering requirements and engaging with clients;
• Experience with SQL, Server‑Side Development, Middleware, Application or Data Integration, API Development, Core Application Systems, Node.js, Groovy, Scala, Spring Cloud, Spring Core, Spring‑Boot, or Spring Data
• Experience with using a message broker, such as Kafka or RabbitMQ
• CompTIA Security+ Certification or higher DoD 8570 cybersecurity certification
• Familiarity with software delivery methodologies such as agile/scrum
• Strong problem‑solving and design skills
• Strong written and oral communication skills.
• Strong interpersonal skills and customer service skills.
• Ability to effectively prioritize and execute tasks in a high‑pressure environment is crucial.
• Ability to work in a self‑guided manner; excellent organizational skills
• Must be a US citizen and hold or be able to obtain a Department of Defense (DoD) SECRET Security Clearance