Verified professional work
Published case study
Analytical pipeline modernisation
Migration of a recurring analytical process from a legacy SQL Server implementation to a modular Databricks and PySpark workflow with automated quality controls.
Organisation-specific details are omitted. The page documents verified responsibilities and reported outcomes without publishing confidential data or internal artefacts.
Context
A recurring analytical process in a financial-data environment. Organisation, dataset and internal implementation details are intentionally omitted.
Problem
The existing calculation depended on a legacy SQL Server workflow and required weeks to complete, making validation, iteration and operational delivery slow.
Scope
- Map the legacy calculation logic and expected outputs.
- Reimplement the workflow with Databricks and PySpark.
- Create reusable, parameterised transformation components.
- Add automated data-quality controls and statistical validation.
- Support technical integration, documentation and handover.
Constraints
- Existing business rules had to remain traceable while the implementation changed.
- Differences between legacy and migrated outputs required explicit reconciliation.
- Organisation-specific data, code and architecture cannot be published.
- The public case study must describe the delivery without exposing confidential information.
Approach
- 01
Frame the migration
Document the calculation rules, dependencies, expected outputs and acceptance criteria before changing the implementation.
- 02
Rebuild the workflow
Translate the process into reusable and parameterised PySpark components running on Databricks.
- 03
Validate the outputs
Apply automated data-quality checks, statistical validation and output reconciliation against the legacy workflow.
- 04
Prepare operational handover
Document execution requirements, known limitations and integration considerations for the teams operating the process.
Deliverables
- Migrated Databricks and PySpark workflow.
- Reusable parameterised transformation components.
- Automated data-quality controls.
- Statistical validation and reconciliation workflow.
- Technical documentation and handover material.
Technologies
- PySpark
- Databricks
- SQL Server
- SQL
- Data quality
- Statistical validation
Evidence
Verified professional result
Calculation cycle
Weeks to approximately two hours
Reported from the delivered professional workflow. Internal timing records and organisation-specific validation artefacts are not public.
Verified implementation evidence
Engineering structure
Reusable parameterised PySpark components
Components incorporated automated data-quality controls and statistical validation.
Limitations
- The underlying code, data and organisation-specific architecture are confidential.
- The public page cannot independently reproduce the original working environment.
- The reported runtime is specific to the original workload, infrastructure and implementation.
- No claim is made that the same runtime improvement would apply to another organisation without assessment.
Production considerations
- Orchestration, retries and failure recovery.
- Data contracts and schema-change handling.
- Access control and sensitive-data governance.
- Monitoring, lineage and operational alerting.
- Compute-cost and performance tuning.
- Reconciliation, rollback and controlled migration.
Service relevance
- SQL or SAS analytical-process migration to PySpark.
- Databricks pipeline and workflow modernisation.
- ETL and data-quality design.
- Analytical-process automation.
- Technical audit and migration roadmap.
- Delivery documentation and handover.