Senior Integration Engineer (Python/APIs/Data)

We are Join.To.IT, a Ukrainian outsourcing company founded in 2012, delivering software solutions across diverse business domains.We focus on building long-term partnerships with our clients and creating solutions that deliver real business impact. Our team consists of experienced professionals who take ownership of their work, value clear communication, and maintain high standards in everything they do.As a Senior Integration Engineer, you will own the integrations between commerce platforms (Shopify, POS, OMS, third-party SaaS) and the data that moves through them for a large replatforming program. The standard is data correctness at the systems-of-record level: orders, inventory and fulfillment must agree across every platform, provably, before and after cutover. This is a long-term, full-time engagement. It is backend integration engineering, not storefront or theme work.

Key Responsibilities

Build and maintain REST and GraphQL integrations with Shopify, POS, OMS and third-party business applicationsImplement OAuth flows, webhook verification and processing, retries, deduplication and error handling for production data flowsHandle the realities of distributed data: duplicate events, out-of-order delivery, partial failures, eventual consistencyDevelop new API integrations with enterprise and SaaS platforms as the program expandsOwn SQL and BigQuery work wherever integrations require data movement or transformationBuild automated reconciliation checks so systems of record stay in agreementTroubleshoot production integrations and data quality issues end to end

Requirements

Fluent English (B2+) and native Ukrainian5+ years of backend engineering focused on API integrations between enterprise or SaaS platformsStrong Python in productionREST and GraphQL integration experience on both consuming and building sidesOAuth, API authentication, webhooks and robust error handling patternsPractical command of idempotency, deduplication and reconciliation designStrong SQL; hands-on data integration or ETL experienceAWS deployment experience with Docker and CI/CDFluent EnglishMinimum 4 hours daily overlap with US Eastern time, full-time availabilityNice to Have:Google BigQueryShopify APIs (Admin GraphQL, webhooks, Fulfillment Orders) or Salesforce Commerce CloudPOS, OMS, ERP or fulfillment system integration experienceEvent-driven integration patterns: queues, event buses, connectorsWe Offer:Office-based, hybrid or remote work formatA comfortable office in Kyiv near Vasylkivska metro station, equipped with a shelter, Starlink, and an uninterrupted power supplyFree gym access near the officePaid vacation and sick leaveCompensation for professional courses and developmentSupportive and loyal management