Senior Tester Data Migration

Gazelle Global; Amsterdam; On-site; EUR 65,000 - 90,000; Full time

Job summary

Gazelle Global is seeking a Senior Tester for a 2–3 year data migration project with a large financial client in Amstelveen. The role focuses on leading data migration testing across the lifecycle, coordinating complex scenarios and ensuring data integrity during migration.

The ideal candidate has proven experience in enterprise testing, strong SQL skills, and fluency in Dutch and English, with the ability to work across legacy and modern systems.

Qualifications

• Senior tester with proven experience in complex enterprise environments.
• Fluent in Dutch and English (spoken and written).
• Strong testing across legacy and modern system landscapes.
• Hands-on SQL and relational databases.

Responsibilities

• Lead the planning, design, execution, and reporting of data migration testing activities.
• Coordinate complex migration test scenarios including validation of calculations, business rules, document migration, and recovery testing.
• Analyze migration outcomes to validate data quality, completeness and accuracy.
• Identify and support defect resolution during migration testing.
• Collaborate with data engineers, IT Business Analysts, project managers, and cross-functional teams to deliver outcomes.
• Document test execution, findings, risks, deviations, and recommendations for auditable migration processes.
• Help continuously improve testing processes to align with governance and quality standards.

Job description

For one of our giant clients based in Amstelveen, we are looking for a Senior Tester - Data Migration.

36-40 hours

2-3 year project

The project and the responsibilities:

As part of the MORSE Programme, you will join a large-scale transformation initiative focused on migrating ING's mortgage portfolio to the Stater platform. Working within the Data Migration & Cleansing workstream, you will play a key role in ensuring that mortgage data is migrated accurately, securely, and in a controlled manner. This is an opportunity to work on a high-impact programme where quality, collaboration, and precision are essential to the successful delivery of one of the bank's strategic initiatives.

In this role, you will lead and coordinate testing activities across the data migration lifecycle, working closely with business and technical stakeholders to ensure the integrity, completeness, and reliability of migrated data.

Responsibilities:

• Lead the planning, design, execution, and reporting of data migration testing activities.
• Coordinate complex migration test scenarios, including calculation validation, business rule verification, document migration, communication testing, pipeline and freeze testing, and fallback and recovery testing.
• Analyse migration outcomes to validate data quality, completeness, and accuracy.
• Identify, coordinate, and support the resolution of defects arising during migration testing.
• Collaborate with data engineers, IT Business Analysts, project managers, and cross-functional teams to deliver successful migration outcomes.
• Support and coordinate end-to-end testing activities across multiple programme workstreams.
• Document test execution, findings, risks, deviations, and recommendations to support a fully auditable migration process.
• Contribute to the continuous improvement of testing processes and ensure testing activities align with programme governance and quality standards.

Skillset (must haves):

• Proven experience as a Senior Tester within complex enterprise environments.
• Fluent in both Dutch and English.
• Strong experience testing across both legacy and modern system landscapes.
• Hands‑on experience with SQL and relational databases.
• Solid analytical and problem‑solving skills.
• Strong stakeholder management and communication skills.
• Experience planning, coordinating, and executing large-scale testing activities.
• Ability to work proactively with excellent attention to detail while maintaining focus on overall programme objectives.

Nice to have:

• Experience with data migration testing.
• Experience within the mortgage lending domain or mortgage systems.
• Previous experience working on large-scale transformation or migration programmes.

Dipika Kaur

Senior Consultant

Desired Skills and Experience

Data Migration Testing, SQL, Relational Databases, Data Validation, Data Quality Testing, Legacy Systems, Modern Systems, Test Strategy, End-to-End Testing, Mortgage Systems Testing