Senior API Migration Engineer (REST APIs – Cloud Migration)

Eliassen Group; Chicago (IL); On-site; USD 89,544 - 103,320; Full time

Job summary

Eliassen Group is seeking a Senior API Migration Engineer in Chicago. This role involves leading the migration and optimization of REST APIs from on-prem Exadata to Oracle Database in the cloud. Responsibilities include validating API performance, coordinating with IT teams, and ensuring security standards during the migration process. Ideal candidates will have 6–10 years of experience in API engineering, with a strong focus on REST API and hands-on experience using Postman and Insomnia. The position offers a competitive hourly rate between $65 to $75.

Qualifications

• 6–10 years of experience in API engineering with a focus on migration work.
• Strong experience with REST API design, testing, and validation.
• Hands-on experience with Postman and/or Insomnia.

Responsibilities

• Lead migration and validation of REST APIs from on-prem Exadata to Oracle Database Cloud.
• Analyze and remediate API compatibility issues.
• Execute API testing and validation using Postman and Insomnia.

Skills

API engineering

REST API design

Postman

Insomnia

Oracle Database

OAuth

Migration strategy

Job description

Remote. Our client seeks a Senior API Migration Engineer to lead the migration, validation, and optimization of REST APIs from on‑prem Exadata to Oracle Database in the cloud. The role focuses on compatibility remediation, authentication alignment, performance tuning, and end‑to‑end validation using tools such as Postman or Insomnia. The engineer will coordinate with IT teams on migration strategy, testing cycles, and release readiness while maintaining reliability and security standards. This is not a net‑new development role.

Rate: $65.00 to $75.00/hr. w2

JN -042026-106219

Responsibilities

• Lead migration and validation of REST APIs from on‑prem Exadata to Oracle Database Cloud.
• Analyze and remediate API compatibility issues across endpoint changes, authentication mechanisms, and data handling logic.
• Execute API testing and validation using Postman and Insomnia.
• Optimize API performance within the Oracle Cloud environment.
• Update backend queries, stored procedures, and integrations impacted by migration.
• Partner with internal IT teams on migration strategy, testing cycles, and release readiness.
• Troubleshoot and resolve API defects during validation cycles.
• Ensure APIs meet performance, reliability, and security standards post‑migration.

Experience Requirements

• 6–10 years of experience in API engineering with a focus on migration work.
• Demonstrated experience migrating REST APIs in enterprise environments.
• Strong experience with REST API design, testing, and validation.
• Experience executing API migration between environments from on‑prem to cloud.
• Hands‑on experience with Postman and/or Insomnia.
• Experience with Oracle databases including Exadata and Oracle Database Cloud.
• Experience modifying API integrations tied to database changes.
• Understanding of authentication mechanisms such as OAuth and token‑based methods.
• Ability to work in large‑scale data environments.
• Preferred experience with Oracle Database Cloud migrations, financial services or regulated environments, large‑scale data systems, and platform modernization initiatives.