Web Services Application Engineer

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. delivers innovative capabilities to the agencies that keep our nation healthy and safe. We apply our domain expertise, data acumen, and technology know-how to achieve breakthrough results for our clients. Working collaboratively, we advance missions and careers through a focus on honesty, integrity, and dependability. We continuously look for talent, excited to join that effort. To learn more about our exciting organization, please visit us at www.unissant.com.

Unissant is seeking a Web Services Application Engineer to support a newly awarded program for a federal health agency. Develop and maintain web service integrations and application interfaces that connect business application systems and shared agency services.

The ideal candidate brings practical delivery experience, sound judgment, and a collaborative approach to maintaining Federal business applications while improving technical capability.

Essential Duties and 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.

Work Experience and Job Skills:

Basic 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 or message 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.

Additional Qualifications:

• Experience with MuleSoft or comparable enterprise integration platforms appropriate to agency web services.
• Experience with Java-based integrations, relational data access, and service modernization.
• Federal shared service integration and API lifecycle documentation experience.
• Experience supporting a Federal IT services environment, preferably within a federal health agency or comparable federal IT environment.
• Experience transferring knowledge from an incumbent team and maintaining reliable services during transition.

Education:

• A degree or relevant coursework in computer science, information systems, engineering, or a related discipline is preferred.

Certificates, Licenses and Registrations:

• A relevant integration platform, application development, or cloud credential is preferred.

Communication Skills:

• Clear verbal and written communication skills, with the ability to coordinate professionally across Government, prime contractor, and subcontractor teams.
• Ability to explain role-specific findings, document decisions and procedures, and communicate risks and recommended actions to the appropriate audience.

Clearance Requirements:

• Must hold or be eligible for a Public Trust Moderate (Tier 2) background investigation and meet applicable federal suitability, badging, and system-access requirements.

Travel:

• Washington, DC.

Environmental Requirements:

• Mainly a routine office environment.
• May be required to lift up to ten (10) pounds
• Flexible in working extended hours

The above statements are intended to describe the general nature and level of work being performed by the individual(s) assigned to this position. They are not intended to be an exhaustive list of all duties, responsibilities, and skills required. Unissant management reserves the right to modify, add, or remove duties and to assign other duties as necessary. In addition, where applicable and available, reasonable accommodation(s) may be made to enable individuals with disabilities to perform essential functions of this position.

Candidate(s) will be required to go through pre-employment screening.

Unissant, Inc. is a proud Equal Opportunity Employer! (EOE; M/F/Disability/Vets)