Data Architect – Mainframe Migration & Modernization

CompanyGazelle Global

LocationLondon Area, United Kingdom

Posted At1/23/2026

UK Visa Sponsorship Analytics

Analytics are greyed out due to low classification confidence (50.0%).

Occupation Type

IT business analysts, architects and systems designers

Occupation Code Skill LevelHigher Skilled

Sponsorship Salary Threshold

£54,900 (£28.15 per hour)

Occupation rate applies

Above analytics are generated algorithmically based on job titles and may not always be the same as the company's job classification. You can also check detailed occupation eligibility, and salary criteria on our UK Visa Eligible Occupations & Salary Thresholds page.

Disclaimer: Hunt UK Visa Sponsors aggregates job listings from publicly available sources, such as search engines, to assist with your job hunting. We do not claim affiliation with Gazelle Global. For the most up-to-date job details, please visit the official website by clicking "Apply Now."

Description

As a Data Architect – Mainframe Migration & Modernization, you will be responsible for moving critical data off the mainframe with zero surprises. Your responsibilities include designing robust Change Data Capture (CDC) strategies, ensuring accurate data landing and transformation, creating optimized data models, and executing a seamless cutover process.

Your responsibilities:

Design and implement CDC pipelines using IBM CDC tools or equivalents, including subscription management, bookmarks, and replay strategies.
Handle complex data encoding transformations, such as EBCDIC to UTF-8 and packed decimal conversions, with validation test suites.
Utilize migration tooling for schema conversion and downstream analytics (Glue, Athena, Redshift), with infrastructure-as-code (Terraform) and CI/CD (GitLab).
Plan and execute cutovers with dual-run validation, reconciliation, rollback strategies, and data governance controls (masking, encryption, IAM).
Develop observability dashboards for lag, throughput, error rates, and cost using CloudWatch/Grafana, with operational runbooks and alerting.
Ensure data quality through pre-migration validation tests and reconciliation against golden sources.

Apply domain-driven design principles to model bounded contexts and aggregate roots.

Architect event-driven systems using CDC as event streams, with replay and orchestration patterns

Translate Db2 schemas to target pipelines(Aurora Postgress preferred), including logical and physical data modelling, referential integrity, and denormalization decisions.

Build integration pipelines from Db2 to target pipelines (Aurora Postgress preferred) via Kafka/S3, ensuring idempotency, ordering, and reliable delivery semantics.

Essential skills/knowledge/experience:

Change Data Capture: CDC design and operations (IBM, Precisely, or equivalent); subscription management, bookmarks, replay, backfill.
Db2 & z/OS knowledge: Db2 catalog, z/OS fundamentals, batch windows, performance considerations.
Relational modelling: Data modelling; normalization, indexing, partitioning; OLTP vs. analytics trade-offs.
Integration patterns: Kafka/ hands-on, CDC-to-target pipelines, UPSERT/MERGE logic; Python/SQL; strong troubleshooting.
Data quality mindset:

Write validation tests before migration; golden-source reconciliation.

Logical data modelling: Entity-relationship diagrams, normalization (1NF through Boyce-Codd/BCNF), denormalization trade-offs; identify functional dependencies and anomalies.

Physical data modelling: Table design, partitioning strategies, indexes; SCD types; dimensional vs. transactional schemas; storage patterns for OLTP vs. analytics.

Normalization & design: Normalize to 3NF/BCNF for transactional systems; understand when to denormalize for queries; trade-offs between 3NF, Data Vault, and star schemas.

Domain-Driven Design: Bounded contexts and subdomains; aggregates and aggregate roots; entities vs. value objects; repository patterns; ubiquitous language.

Event-driven architecture: Domain events and contracts; CDC as event streams; idempotency and replay patterns; mapping Db2 transactions to event-driven architectures; saga orchestration.

CQRS patterns: Command/query separation; event sourcing and state reconstruction; eventual consistency, when CQRS is justified for mainframe migration vs. overkill.

Database internals: Index structures (B-tree, bitmap, etc.), query planning, partitioning strategies; how Db2 vs. PostgreSQL differ in storage and execution.

Data quality & validation: Designing test suites for schema conformance; referential integrity checks; sampling and reconciliation strategies.

Desirable skills/knowledge/experience:

IBM zDIH patterns, zIIP tuning.
COBOL copybook/VSAM ingestion experience.
Postgress SQL Data Architecture, PostgreSQL/Aurora data modelling