Web Services & API Integration Engineer (Federal)

Unissant; Washington (District of Columbia); Hybrid; USD 110,000 - 140,000; Full time

Job summary

Unissant, Inc. seeks a Web Services Application Engineer to support a federal health agency program. Develop and maintain web service integrations and application interfaces connecting business systems and shared agency services.

The ideal candidate will bring hands-on delivery experience, sound judgment, and a collaborative approach to maintaining Federal business applications while improving technical capability. On-site support in the Bethesda, MD area may be required.

Qualifications

• 5 years experience developing application interfaces, web services, and enterprise integration components.
• Hands-on experience with HTTP-based APIs, structured data formats, and schema validation.
• Ability to implement authentication, authorization, error handling, and secure data exchange in service code.
• Experience troubleshooting interface failures using logs, request traces, and application or database evidence.
• Experience with automated tests, source control, and controlled deployment of integration changes.
• Ability to coordinate interface requirements and changes with producers, consumers, and operations teams.
• Ability to document work clearly, protect sensitive program information, and collaborate across Government and contractor teams.
• Ability to meet federal suitability and access requirements and provide on-site support in the Bethesda, Maryland area as directed.

Responsibilities

• Analyze service requirements, interface contracts, schemas, authentication needs, and downstream dependencies.
• Develop and maintain web service endpoints, integration flows, mappings, and application adapters in the approved stack.
• Implement validation, transformation, error handling, transaction controls, and diagnostic logging for service interactions.
• Create unit and integration tests for interface behavior, failure paths, and data exchange accuracy.
• Investigate failed service calls, mapping defects, and application integration incidents with consuming system teams.
• Maintain versioned interface documentation and coordinate changes to avoid breaking existing consumers.
• Support secure builds, code review, deployment, rollback preparation, and post-release service verification.
• Support transition knowledge transfer and maintain current technical or process documentation for assigned responsibilities.
• Coordinate assigned work with program leadership, Government stakeholders, and related teams; report blockers and dependencies promptly.
• Use Government-approved tools and handle program data within authorized environments. Validate any AI-assisted output before it informs delivery decisions.

Skills

Enterprise integration

Web services

API development

Testing automation

Documentation

Secure data exchange

Coordinate with teams

Federal suitability

Education

CS related degree

Tools

MuleSoft

Java

Relational DBs

Job description

Unissant, Inc. seeks a Web Services Application Engineer to support a federal health agency program. Develop and maintain web service integrations and application interfaces connecting business systems and shared agency services.

The ideal candidate will bring hands-on delivery experience, sound judgment, and a collaborative approach to maintaining Federal business applications while improving technical capability. On-site support in the Bethesda, MD area may be required.