Integrations Engineer — APIs, EDI & Data Flows

OneRail USA; Kraków; Hybrid; PLN 145,000 - 179,000; Full time

Job summary

OneRail is seeking an Integration Specialist to design, configure, test, and support customer integrations across the implementation lifecycle. You will bridge customers, Implementation Managers, Product, and Engineering to ensure seamless connectivity between customer systems and the OneRail platform.

The ideal candidate is highly technical, customer-focused, and enjoys solving integration challenges in a fast-paced SaaS environment, with hybrid work in Kraków, Poland and salary of 13 000–16

Qualifications

• Bachelor's degree in Computer Science, Information Systems, Engineering, or equivalent experience.
• 2–5 years of experience implementing SaaS software or enterprise integrations.
• Experience working with REST APIs.
• Familiarity with JSON, XML, CSV, and data transformation.
• SQL knowledge for data validation.
• Understanding authentication methods such as OAuth and API Keys.
• Experience with Postman or similar API testing tools.
• Familiarity with middleware/iPaaS platforms (MuleSoft, Boomi, etc.).
• Ability to manage multiple implementation projects simultaneously.
• Experience with logistics, transportation, supply chain, or retail technology.
• Understanding webhooks and event-driven architecture.
• Experience working in a customer-facing SaaS environment.
• Strong troubleshooting and analytical skills.
• Advanced proficiency in English & Polish, both written and spoken (B2+).

Responsibilities

• Design, configure, and implement customer integrations using APIs, webhooks, SFTP, EDI, and flat-file exchanges.
• Lead technical discovery sessions to understand customer system architecture and business workflows.
• Configure integration mappings, authentication methods, and data transformations.
• Validate end-to-end data flow prior to production launch.
• Partner with Implementation Managers to develop technical implementation plans.
• Build and execute integration test plans.
• Troubleshoot API connectivity, data validation, and workflow issues.
• Document technical configurations and implementation decisions.
• Create extensive and detailed process and integration flows of customers' existing infrastructure and how it will connect to OneRail.
• Ensure integrations meet security and performance requirements.
• Serve as the technical liaison between Customer Success, Product, Engineering, and customers.
• Escalate product defects and enhancement requests with clear technical documentation.
• Collaborate with Engineering during complex implementations requiring custom development.
• Assist Support with complex post-go-live integration issues when necessary.
• Develop reusable integration templates and documentation.
• Improve implementation processes through automation and standardization.
• Create internal knowledge base articles and customer-facing technical guides.
• Identify opportunities to reduce implementation timelines through repeatable solutions.

Skills

REST APIs

JSON

XML

CSV

SQL

OAuth

API Keys

Postman

MuleSoft

Boomi

English

Polish

iPaaS

Education

Bachelor's degree in Computer Science/Information Systems/Engineering

Tools

MuleSoft

Boomi

Job description

OneRail is seeking an Integration Specialist to design, configure, test, and support customer integrations across the implementation lifecycle. You will bridge customers, Implementation Managers, Product, and Engineering to ensure seamless connectivity between customer systems and the OneRail platform.

The ideal candidate is highly technical, customer-focused, and enjoys solving integration challenges in a fast-paced SaaS environment, with hybrid work in Kraków, Poland and salary of 13 000–16