Data Functional Analyst

Oliver James Group; Brussel; On-site; EUR 65,000 - 90,000; Full time

Job summary

Oliver James Group is partnering with a leading enterprise to migrate core legacy systems from Adabas/Mainframe to PostgreSQL. We seek a Data Functional Analyst to bridge legacy business logic and modern database architecture, working closely with Data Engineers and DBAs to define data mappings and ensure a high-integrity migration.

You will document data dictionaries, mapping rules, and lineage, guide ETL/ELT design, and serve as the functional lead translating complex business rules for the

Qualifications

• 3 years of experience as a Data Functional Analyst, Business Data Analyst, or Data Consultant on large-scale data transformation projects.
• Strong, mandatory expertise in PostgreSQL and advanced proficiency in SQL and relational data modelling concepts.
• Solid functional understanding of Mainframe database environments (knowledge of Adabas is nice to have, but not mandatory).
• Hands-on experience working on complex legacy-to-relational data migration projects.

Responsibilities

• Legacy Data Analysis & Mapping: Deep-dive into Mainframe data structures and define accurate functional target mappings to PostgreSQL relational schema.
• Technical & Functional Guidance: Act as the primary functional advisor for Data Engineers and DBAs, writing clear functional specifications to guide ETL/ELT pipeline development and schema design.
• Data Quality & Reconciliation: Design data validation strategies, define test scenarios, and execute cross-database reconciliation checks (Mainframe legacy vs. PostgreSQL) to guarantee 100% data integrity and consistency.
• Data Lineage & Documentation: Maintain comprehensive data dictionaries, mapping rulebooks, and lineage documentation throughout the migration lifecycle.
• Cross-Functional Collaboration: Serve as the functional point of contact for resolving legacy data ambiguities and translating complex business rules for the technical delivery team.

Skills

PostgreSQL

SQL

Relational data modeling

Mainframe knowledge

Adabas knowledge (nice to have)

Data migration experience

Job description

About the Role

Oliver James is partnering with a leading enterprise organization migrating its core legacy systems from Adabas (Mainframe) to PostgreSQL.

We are seeking a Data Functional Analyst to bridge the gap between legacy business logic and modern database architecture. Working directly alongside Data Engineers and DBAs, you will define data mappings and ensure a seamless, high-integrity migration.

Key Responsibilities

• Legacy Data Analysis & Mapping: Deep-dive into Mainframe data structures and define accurate functional target mappings to PostgreSQL relational schemaq.
• Technical & Functional Guidance: Act as the primary functional advisor for Data Engineers and DBAs, writing clear functional specifications to guide ETL/ELT pipeline development and schema design.
• Data Quality & Reconciliation: Design data validation strategies, define test scenarios, and execute cross-database reconciliation checks (Mainframe legacy vs. PostgreSQL) to guarantee 100% data integrity and consistency.
• Data Lineage & Documentation: Maintain comprehensive data dictionaries, mapping rulebooks, and lineage documentation throughout the migration lifecycle.
• Cross-Functional Collaboration: Serve as the functional point of contact for resolving legacy data ambiguities and translating complex business rules for the technical delivery team.

Requirements & Qualifications

• Functional Data Expertise: 3 years of experience as a Data Functional Analyst, Business Data Analyst, or Data Consultant on large-scale data transformation projects.
• Database & SQL Skills: Strong, mandatory expertise in PostgreSQL and advanced proficiency in SQL and relational data modelling concepts.
• Mainframe Experience: Solid functional understanding of Mainframe database environments (knowledge of Adabas is nice to have, but not mandatory).
• Migration Track Record: Hands-on experience working on complex legacy-to-relational data migration projects.

Language Skills

• Fluent English (written and spoken).
• Professional fluency in French and/or Dutch (essential for local team and business stakeholder collaboration).

Communication & Mindset

Excellent analytical skills, rigorous attention to detail, and the ability to articulate complex functional rules clearly to technical teams.