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# API Integration Engineer

- **Company:** Koniag Services, Inc.
- **Location:** Washington, DC, United States
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Application Programming Interfaces (APIs), Audit Trail, User Authentication, Information Systems, Data Governance, Extract Transform Load (ETL), Relational Databases, Domain Name System (DNS), Network Interface Controllers, File Transfer, JSON, Simple Object Access Protocol (SOAP), Systems Integration, Extensible Markup Language (XML), Flexi (Photoshop Plugin), Appian, Information Technology, Enterprise Integration, Restful APIs, Api Management, Web Api
- **Published:** October 31, 2026
- **Apply:** https://www.clearancejobs.com/jobs/9281779/api-integration-engineer

## About the Role

* Bachelor's degree in computer science, engineering, information systems, or a related field; additional relevant experience may substitute for education.
 * Five or more years designing and supporting enterprise integrations and APIs.
 * Experience with REST, SOAP, JSON, XML, schemas, authentication, certificates, message/file transfer, API testing, and production monitoring.
 * Experience integrating workflow platforms, relational databases, conventional applications, and external systems under controlled change processes.
 * U.S. citizenship and the active security clearance or eligibility required for the assigned work by the start of performance, with ongoing eligibility thereafter.
 * Ability to communicate clearly with Government, technical, and business stakeholders and to maintain accurate work records in approved systems.
 * Ability to protect Controlled Unclassified Information and classified information, when assigned, and comply with required access, training, and handling procedures.

Education and Experience Desired:

 * Experience with Appian Integration Objects, Connected Systems, web APIs, plug-ins, or integration SDKs.
 * Experience with PIEE, GEX, GFEBS, SAM.gov, FPDS, VANTAGE, PDS/PRDS, or other acquisition interfaces.
 * Experience supporting interfaces across IL-5 and IL-6 boundaries without assuming cross-domain data movement., * API and enterprise integration engineering
 * Interface security and identity
 * Schemas, transformations, and data standards
 * Monitoring, fault isolation, and recovery
 * ICDs, partner coordination, and controlled cutover

## Description

* Inventory inbound and outbound interfaces, owners, classifications, endpoints, authentication, schemas, dependencies, approval lead times, monitoring, and recovery requirements.
 * Develop and maintain interface decision matrices, Interface Control Documents, data mappings, record layouts, and operational procedures.
 * Design and implement secure REST, SOAP, message, file-transfer, and event-based integrations using approved Appian and conventional-code patterns.
 * Create API facades and adapters that preserve legacy contracts while capabilities and schemas transition into a new solution.
 * Support integrations involving GEX, GFEBS, FPDS/SAM, VANTAGE, EDA, Closeout, and other authorized PIEE or Army services.
 * Implement approved authentication, authorization, certificates, secrets, encryption, validation, error handling, retry, idempotency, and audit logging.
 * Develop automated contract, schema, transformation, negative-case, exception, performance, and recovery tests.
 * Instrument interfaces with correlation identifiers, health checks, structured logs, alerts, and dashboards for rapid fault isolation.
 * Coordinate network, identity, DNS, certificate, firewall, boundary, and partner-system changes before cutover.
 * Support interface migration, parallel operation, conformance, security, regression, operational acceptance, rollback, and retirement.