ASHOK
RAJENDRAN
I build modern data infrastructure that converts raw data into meaningful insights. Currently working with large-scale data systems, with experience across BigQuery, Snowflake, Spark, Airflow, Python & SQL.
Current Role
Best Buy™ India Apr 2025 - Present
Software Engineer - II (Data & Cloud)
Building cloud-native data models and pipelines on Google Cloud and Snowflake that power subscription revenue reporting, conditional offer analytics, and secure partner data collaboration, while modernizing on-premises data assets and strengthen cloud foundation and DevOps capabilities.
Major Contributions:
- Designed and built a BigQuery data model to consolidate active subscription customers for Best Buy, enabling tracking of $1.2B in annual subscription revenue and providing a unified view of customer subscription data for reporting and analysis
- Architected and successfully developed a complex BigQuery data model for Best Buy's conditional offer sales, integrating 6 product-category-specific tables with intricate business logic to calculate offer amounts across products with varying warranty structures and frequently changing business rules
- Designing and implementing a Snowflake Data Clean Room for Best Buy to establish a secure environment for joint analytics with vendor partners without exposing underlying raw data
- Successfully modernized and rebuilt data pipelines in Google Cloud Platform (GCP) to migrate on-premises data assets to the cloud, reducing infrastructure dependency and lowering operational costs by approximately 30%
- Engineered and deployed a Google Cloud Workflow to process 5 customer subscription assets in parallel, serving as the source of truth for more than 20 years of customer subscription lifecycle data
- Successfully implemented DevOps and cloud foundation capabilities as part of the Cloud Data Foundation team, including secure project provisioning, secret management, Workload Identity Federation (WIF), and OAuth integration
Previous Experience
Carelon Global Solutions Jan 2021 - Mar 2025
Senior Software Engineer - Data Engineering
Focused on developing scalable data models and pipelines using Python and SQL across AWS and GCP environments to process high-volume healthcare claims data, while ensuring compliance with privacy and security standards.
- Designed and successfully developed an ETL pipeline using Python and SQL on Google Cloud to monitor and process $250M of finalized claims daily for the MBM Commercial accounting model
- Architected and built an AWS Glue-based ETL framework to support incremental and bulk data movement across Amazon S3, enabling secure and efficient exchange of 200 TB of incentives data with external vendors
- Strategically designed and reviewed enterprise data models and architecture solutions, incorporating data governance, security, and PHI/PII risk mitigation requirements for US-based clients
- Successfully optimized complex Snowflake SQL workloads on large datasets and contributed to code reviews, data quality improvements, and secure development practices
- Successfully managed and mentored a team of 8+ associates on Big Data technologies, Hadoop, data lake architecture, and development practices, improving technical delivery across the team
Accenture Inc. Sept 2017 - Dec 2020
Software Engineer - Data Engineering
Led performance optimization and framework enhancement efforts for big data ingestion tools, supporting cross-team collaboration and large-scale ETL operations in a Hadoop ecosystem.
- Successfully enhanced a Hive partition cleanup framework, reducing execution time from approximately 30 minutes to less than 1 minute per table (approximately 98% reduction) and earning the "Best of the Month" award at Accenture BDF
- Engineered and applied a PySpark-based test automation framework using Python and shell scripting for validating the conversion of StreamSets ETL pipelines to Spark jobs, reducing testing effort from 8 hours to under 30 minutes per table
- Redesigned and successfully enhanced a centralized RDBMS-to-Hadoop ingestion framework using Shell, PySpark, Sqoop, Hive, and HBase, scaling it to support 1,800+ production data pipelines
- Successfully engineered an automated auditing framework to validate HBase entries across 1,600+ StreamSets pipelines, with automated failure logging and email notifications that eliminated nearly 2 days of manual effort
- Designed and built an automation tool to scan audit data across HBase and identify missing data loads between Hadoop and Snowflake, supporting validation across 1,000+ tables
Skills
Data Warehousing
- Snowflake
- BigQuery
- Teradata
- Hadoop
Cloud Platforms
- AWS
- Google Cloud
Scripting/Programming
- SQL
- Python
- Apache Spark
- Shell Scripting
Core Competencies
Data Engineering & Architecture
- Data Modeling & Warehousing
- ETL/ELT Pipeline Development
- Data Quality & Governance
- Security & Compliance
Cloud & Pipeline Engineering
- Distributed Systems
- Pipeline Orchestration
- CI/CD Automation
- Scalable Solutions
Data Operations & Management
- Agile Methodologies
- Project Management
- Technical Documentation
- Technical Training
Personal Projects
Airlines Analytical Simulation
Designed a production-grade airline analytics platform on Google BigQuery to simulate aviation operations, enabling delay analysis, overbooking management, passenger intelligence, and route performance insights.
Retail Sales Analytics
Designed and implemented a PySpark-based retail sales analytics pipeline in Databricks to analyze customer purchasing patterns, enabling product affinity insights and ETL-driven data processing using Delta Lake.
GCS Big File Transfer
Developed an event-driven Google Cloud Function to monitor GCS uploads and automatically transfer large files to archival storage with logging and folder structure preservation.
Coding Profiles
Certifications
AWS Certified Data Engineer - Associate
Given by:Amazon Web Services
Credential URL:View credential
Expiry Date:Dec 2027
Google Cloud Professional Data Engineer
Given by:Google Cloud
Credential URL:View credential
Expiry Date:Feb 2028
AWS Certified AI Practitioner
Given by:Amazon Web Services
Credential URL:View credential
Expiry Date:Nov 2028
Google Cloud Generative AI Leader
Given by:Google Cloud
Credential URL:View credential
Expiry Date:Jan 2029
Achievements
Education
Anna University, Panimalar Engineering College, Chennai.Aug 2013 - Aug 2017
Bachelor of Engineering in Electrical and Electronics Engineering
Completed undergraduate studies with First Class, maintaining consistent academic performance throughout.
Final Year Project
DC-DC Converter for BLDC Motor Using Ultracapacitor & Battery
Designed and implemented a hybrid power supply system to improve efficiency and performance in Brushless DC motor applications.
Beyond Code
Hiking
Hiking and trekking the Himalayas. Love exploring new trails and challenging myself.
Basketball
Occasionally play basketball and enjoy staying active through the sport.
Geopolitics
Listen to a lot of geopolitical news and analysis.
Chess
Enjoy playing chess and working through tactics puzzles to sharpen strategic thinking.
Beyond my professional life, I'm an avid hiker, play chess, basketball, and a keen follower of global affairs. I believe in maintaining a healthy work-life balance and continuously expanding my horizons through new experiences and challenges.