
Rajachozhan Iyappan
Data Engineer
Salary / Daily rate
Coventry, UK
Freelance, open to permanent contract
Skills
About me
Intro
Results-oriented Azure Data Engineer with over 4 years of experience in designing, building, and optimizing big data and cloud-based ETL/ELT pipelines using tools like ADF, Databricks, Fabric, Synapse, Delta Lake, and Power BI. Proven ability in building metadata-driven pipelines, implementing data governance, and delivering robust BI solutions with measurable business impact. Skilled in Python, PySpark, and SQL, with a strong focus on performance optimization, automation, and stakeholder management. Experienced in integrating data from SAP, Cosmos DB, into unified analytics platforms. Proficient in implementing data lineage and cataloging using Purview and Unity Catalog.
Work experience
Data Engineer
Sys Global
Feb 2024 - Oct 2025
1 year 9 months
– Collaborated with business stakeholders and analysts to gather data requirements, define KPIs, and build scalable data solutions using Azure Data Services, improving reporting turnaround time by 35% and enhancing cross-departmental alignment through effective communication and documentation practices. – Designed and implemented greenfield project using Databricks, Synapse, Microsoft Fabric, and Unity Catalog, enabling real-time analytics and reducing data latency and operational delays by 40%. – Leveraged PySpark in Databricks to optimize large-scale ETL pipelines, reducing data processing time by 50% for customer engagement datasets sourced directly from Dataverse and external APIs. – Developed automated ETL pipelines using Python and Azure Data Factory (ADF) that validate, test, and load data, eliminating manual effort and improving data accuracy by 30% across business domains. – Built metadata-driven pipelines with Delta Lake, Azure Purview, ADLS, and Python, enabling scalable, governed data movement in both Databricks and ADF environments with dynamic schema handling. – Integrated Power BI dashboards with curated Delta tables to deliver near real-time insights on CRM customer journeys, reducing dashboard refresh times and reporting delays by 45% across regions. – Architected a Delta Lake-based data lakehouse for storing structured and semi-structured data with schema enforcement and time travel, improving audit readiness and regulatory compliance for all departments. – Designed a hybrid data warehouse and data lake architecture using Synapse and ADLS, supporting both historical and real-time analytics, with a 40% performance improvement on large-scale queries. – Configured IAM and RBAC policies in Azure and Unity Catalog to enforce fine-grained access controls, ensuring role-based segregation and boosting data security compliance across data teams. – Enabled data quality monitoring by embedding custom Python scripts within ADF pipelines, detecting anomalies and reducing recurring data issues by 20% in weekly operational reports. – Built reusable ADF templates for parameterized pipelines, improving development consistency and boosting productivity by 30% across distributed engineering and analytics teams globally. – Automated pipeline deployment using Azure DevOps CI/CD, minimizing manual steps and reducing deployment time and errors by 90%, ensuring consistent releases across all environments. – Implemented incremental data loading and watermarking strategies in ADF and Databricks pipelines, ensuring efficient processing of only changed records and reducing overall data ingestion time by 35%.
Data Engineer
Reliance Capital
May 2021 - Aug 2023
2 years 4 months
– Collaborated closely with cross-functional teams and business users to define data strategy and reporting requirements, improving business alignment and reducing change requests by 25%. – Initiated and led a new project implementation using Databricks, Azure Synapse, Unity Catalog, PySpark, and Microsoft Fabric, delivering production-ready pipelines within 3 months and enabling rapid, scalable data insights for key business units and analytical workflows across the enterprise. – Used PySpark in Databricks for efficient batch processing of millions of records daily, reducing data ingestion time from 2 hours to 30 minutes and improving operational efficiency significantly. – Developed Python modules for ETL automation and unit test frameworks, enabling test-driven development and improving code reliability and reusability by 40% across multiple development environments, promoting standardized practices and reducing technical debt across data engineering teams. – Engineered metadata-driven frameworks in Databricks and ADF using Delta Lake and Python, allowing pipeline reuse across 6+ domains and reducing code duplication in multi-team setups. – Integrated Power BI dashboards and published them to workspaces connected to Delta tables, providing real-time KPIs and improving dashboard refresh efficiency by 50% across business operations. – Built scalable data pipelines to transfer data from Cosmos DB to Azure SQL DB, and later to Amazon S3/Redshift, effectively reducing data redundancy and overall cloud storage cost by 20%. – Designed a robust data lake architecture using ADLS and Delta Lake, supporting version control, schema evolution, and rollback, facilitating easy data governance and compliance auditing. – Configured RBAC and IAM policies in Unity Catalog and Azure, enforcing strong data governance practices and ensuring GDPR compliance across regional and international data zones. – Migrated legacy ETL jobs to Apache Airflow-orchestrated Databricks notebooks, resulting in a 60% improvement in pipeline monitoring, scheduling efficiency, and failure recovery response. – Integrated Azure DevOps pipelines for CI/CD deployment of notebooks and configuration files, reducing environment drift and improving release cycles across all data engineering environments. – Implemented custom alerting mechanisms for pipeline failures and SLA breaches using Azure Monitor and Log Analytics, cutting pipeline downtime and alert response time significantly.
Data Engineer
Sanofi
Sep 2019 - Apr 2021
1 year 8 months
– Led data requirement analysis with finance and supply chain stakeholders, improving project planning efficiency and reducing scope creep by 20% across multiple enterprise-wide data initiatives. – Spearheaded a new project implementation using Databricks, PySpark, Unity Catalog, and Synapse, resulting in an enterprise-grade data lake with a 99.9% uptime SLA and enhanced reliability. – Optimized large-scale SSIS to ADF pipeline migration using PySpark in Databricks for high-volume data loads, reducing daily job runtime by 55% and enabling faster downstream reporting. – Created Python-based test scripts to validate data lineage and integrity in ETL pipelines, boosting accuracy and expanding automation test coverage by 60% in critical production systems. – Built metadata-driven pipelines with Delta Lake, Azure Purview, and Python, facilitating complete data cataloging and promoting pipeline reusability across both SAP and SQL Server data sources, while ensuring enterprise-wide consistency, scalability, and governance in enterprise data operations. – Integrated Power BI with Delta Lake and SAP BO data layers, developing interactive, executive-level dashboards and reports, significantly improving data visibility and decision-making by 50%. – Designed a Delta Lake and ADLS-based data lake architecture to standardize data ingestion from SAP BW and Azure SQL, enhancing long-term data reusability and storage efficiency organization-wide. – Created Tabular and Multi-dimensional models in SQL Server Analysis Services (SSAS) for OLAP queries, reducing end-user reporting latency by 30% and improving analytics performance and user experience. – Established role-based access controls (RBAC) using Git and Azure policies, ensuring secure collaboration and strict compliance with data privacy adherence across cross-functional data engineering teams. – Migrated existing SAP BO reports to Power BI, building a centralized self-service analytics platform, drastically reducing IT support dependency for ad-hoc reporting across business units. – Deployed and maintained source control and versioning via Git, improving change management, enabling traceability, and reducing rollback efforts due to unexpected deployment errors and issues. – Conducted UAT, coordinated deployment, and provided post-production support, achieving a 95% first-time acceptance rate from key business stakeholders across finance and supply chain.
Education
Coventry University
Master's, Data Science
2023 - 2024
1 year 1 month
SRM University, Chennai, India.
Bachelor's, Mechanical Engineering
2015 - 2019
4 years 1 month
Licenses & certifications
Microsoft Certified: Azure Data Engineer Associate (DP-203)
Issued: –