Integration QA Engineer

Leadex Systems is hiring an Integration QA Engineer to work on a greenfield fintech project for a UK-based client. The role focuses heavily on backend, system, and integration testing across complex external services such as payment gateways, KYC providers, banking APIs, and third-party financial systems. You will work within a cross-functional team alongside MuleSoft developers, Salesforce specialists, and project stakeholders to ensure the reliability, security, and accuracy of critical financial workflows. The role involves planning and executing end-to-end integration testing, validating data transformations across the MuleSoft and Salesforce ecosystem, and ensuring external API interactions behave correctly under different scenarios and edge cases. You will also contribute to defining QA processes, regression testing strategies, and integration workflows for a product being built from scratch. Regular collaboration with UK-based stakeholders and transparent reporting on quality metrics are also important parts of the role.

Candidates should have at least 3 years of QA experience with strong expertise in backend, system, and integration testing. Proven experience testing third-party integrations, external APIs, and webhooks is essential. Applicants are expected to have advanced knowledge of API testing tools such as Postman or SoapUI and strong SQL skills for backend validation and data verification. A strong understanding of fintech systems, transaction flows, and data security principles is required. The ideal candidate should be comfortable working in early-stage product environments where testing processes and workflows must be created and refined from the ground up. Strong English communication skills are important due to direct collaboration with British stakeholders. Experience with MuleSoft, Salesforce, or fintech ecosystems in the UK market is considered a strong advantage.