Shanthi is available for hire
Hire ShanthiShanthi Viswanathan
Verified Expert in Engineering
SQL Developer
Jersey City, NJ, United States
Toptal member since December 13, 2019
Bio
Shanthi has over 25 years of experience developing applications using various technologies. As an architect, she's executed several web-based applications, integrations, data migrations, data conversions, and data warehousing projects with significant hands-on as well as leadership responsibilities. She keeps up-to-date with the latest technologies and can effectively match the business needs with those technologies.
Portfolio
CritiCoach.com
Amazon Web Services (AWS), Amazon Lightsail, PostgreSQL, Python 3, Bash, React...
Open Practice Solutions
Python, SQL, Redshift, Amazon QuickSight, Data Visualization...
Pfizer
Python, R, SQL, Redshift, DataGrip, Oracle SQL Developer, Atom, Neo4j...
Experience
- SQL - 20 years
- Data Architecture - 7 years
- PostgreSQL - 4 years
- Python 3 - 3 years
- Neo4j - 2 years
- ELK (Elastic Stack) - 2 years
- R - 1 year
- Prompt Engineering - 1 year
Preferred Environment
R, Python, Linux, Neo4j, Oracle, React, Flask API, Prompt Engineering, ChatGPT API, PostgreSQL
The most amazing...
...project I've designed and coded determined the price of products based on sales promotions, order quantity, location, and customer status.
Work Experience
Technology Architect | Full-stack Developer
2025 - PRESENT
CritiCoach.com
- Developed an AI-based app in less than three months that's now being used in universities.
- Enhanced app responses through prompt engineering and used ChatGPT to refine prompts.
- Deployed the app in Amazon Lightsail for cost effectiveness, and integrated Mailgun for notifications.
Technologies: Amazon Web Services (AWS), Amazon Lightsail, PostgreSQL, Python 3, Bash, React, Flask API, Gunicorn, NGINX, Prompt Engineering, ChatGPT API, Supabase, Cloud Infrastructure, APIs, Business Intelligence (BI), Dashboards, Data Integration, API Integration, JSON, ETL Pipelines, Data Cleaning, CSV File Processing, ETL, Artificial Intelligence (AI), Systems Engineering
Data Engineer
2022 - 2023
Open Practice Solutions
- Developed an ETL to bring data from multiple sources into a target reporting database.
- Automated the process of connecting to different data sources based on input parameters. Parameterized the selection of data from tables and columns in each data source.
- Built AWS Lambda functions and scheduled batch jobs to process data on a routine basis.
- Added error handling so that after a failed run, notifications are sent, and data is reset without impacting the user interface.
Technologies: Python, SQL, Redshift, Amazon QuickSight, Data Visualization, Amazon Web Services (AWS), AWS Lambda, AWS Step Functions, Amazon S3 (AWS S3), Data Migration, Data Science, Database Design, Cloud Infrastructure, APIs, Business Intelligence (BI), Enterprise Data Warehouse (EDW), Dashboards, Data Build Tool (dbt), Data Integration, API Integration, JSON, ETL Pipelines, Data Cleaning, Large Data Sets, CSV File Processing, ETL, Data Pipelines, TypeScript, REST APIs, HIPAA Compliance, Reporting
Data Engineer
2020 - 2023
Pfizer
- Technical architect in the development of ETLs to bring data from the Redshift data lake to project-specific Snowflake, Postgres, and Neo4j databases to represent complex relationships across different objects used for quality control.
- Built logic to provide restart capability in case of failures during the load. Produced several data pipelines and improved the performance of these ETLs.
- Developed a data model to support the UI for capacity planning, schedule optimization in labs, quality assurance, and resource management projects.
- Developed ETLs to forecast demand and perform inspection analyses using historical data.
- Designed, developed, and implemented search functionality using Elasticsearch across multiple languages. Converted the initial Postgres search logic to Elasticsearch for better performance.
- Built complex logic to reconcile source and target data. Added error handling such that after a failed run and reconciliation, notifications are sent, and data is reset in a manner that does not impact the front-end applications.
Technologies: Python, R, SQL, Redshift, DataGrip, Oracle SQL Developer, Atom, Neo4j, Data Architecture, Data Modeling, Kubernetes, Splunk, Apache Airflow, PostgreSQL, Amazon Web Services (AWS), ELK (Elastic Stack), Elastic, Snowflake, Node.js, Microsoft Visual Studio, Data Migration, Data Science, Database Design, Cloud Infrastructure, Business Intelligence (BI), Enterprise Data Warehouse (EDW), Dashboards, Data Integration, API Integration, JSON, ETL Pipelines, Data Cleaning, Large Data Sets, CSV File Processing, ETL, Data Pipelines, HIPAA Compliance, Reporting
Data Integration Architect
2017 - 2019
Exelon
- Delivered integrations across several systems with the enterprise asset suite management system.
- Led a 15-member team of offshore and onsite developers in the delivery of all integrations, data migrations, and decommissioning of old systems.
- Migrated customers, products, and associated objects for over five million clients and 200,000 products using Informatica and Oracle Fusion middleware technologies.
- Used GitHub as a source repository and Maven and Jenkins for continuous deployment.
- Designed the data architecture for data migration and data cleansing of the homegrown asset management systems.
- Designed data pipelines to move data from the asset management system into a data lake.
Technologies: Python, Oracle Database, Informatica ETL, Oracle Fusion Middleware, Data Migration, Database Design, Enterprise Data Warehouse (EDW), API Integration, PySpark, JSON, Data Cleaning, CSV File Processing, ETL, Oracle ADF, Integration, REST APIs, Oracle Integration Cloud (OIC)
Enterprise Architect
2015 - 2017
Biogen
- Managed product and vendor selection, technical architecture, data conversion and migration, proof-of-concept, and design standards.
- Managed the LMS-related data migration from SumTotal to SAP Success Factors. Delivered all integrations between the LMS and other systems.
- Managed the reporting framework to produce dashboards and customized reports by integrating data from several of Biogen's core systems. The architect for reporting solutions using Informatica, Spark, and Tableau.
- Loaded 23AndMe data into an in-house MongoDB database and built data pipelines to map clinical results.
Technologies: Oracle Fusion Middleware, MongoDB, R, Python, SQL, Oracle, Oracle E-Business Suite (EBS), Data Migration, Database Design, Enterprise Data Warehouse (EDW), Fivetran, API Integration, JSON, ETL, Oracle ADF, Systems Engineering, Enterprise Architecture, Integration, REST APIs, Content Management Systems (CMS)
Architect
2014 - 2015
GE, Celgene, DirecTV
- Acted as the release captain responsible for the implementation of a heavily customized web-based Java application built on Oracle HR.
- Acted as the enterprise architect responsible for defining the roadmap for the integration of LifeShield operations with DirecTV using Oracle Fusion Middleware technologies.
- Defined the roadmap, implemented MDM, and consolidated integrations. Planned the roadmap for customer MDM at Celgene.
Technologies: Oracle Fusion Middleware, Master Data Management (MDM), Data Migration, API Integration, Data Cleaning, Oracle ADF, Systems Engineering, Enterprise Architecture
Architect
2011 - 2014
SelectComfort, CanonEurope, Panduit
- Acted as the solution architect responsible for delivering an integrated web experience to distributors and partners using Webcenter Suite, UCM, Oracle EBusiness modules (OM, AR), Heiler, and other client applications.
- Spearheaded the project as the enterprise architect to bridge the business needs with the technology necessary to meet the business goals for eCommerce, master data management, document management, and product pricing.
- Integrated the new eCommerce platform Hybris with existing back-end systems like Siebel, Oracle EBS, and SQL Server.
- Responsible for the design, development of data marts, data warehouse, and OBIEE reports at Canon Europe, as a BI architect.
Technologies: Oracle Fusion Middleware, eCommerce, SAP Hybris, Business Intelligence (BI), Data Cleaning
Technical Manager
2007 - 2010
Accenture
- Contributed to the "SOA Go-to-Market" strategy team and worked closely with client partners, senior executives, and Oracle Sales to close deals.
- Executed several projects for Accenture clients using Oracle technologies.
- Developed the canonical model based on OAGIS standards by closely working with business architects and leads.
Technologies: Oracle Data Integrator (ODI), Service-oriented Architecture (SOA), Oracle Fusion Middleware, XQuery, Python, Aerospace & Defense, SQL, Oracle, Microsoft Excel, Visual Basic for Applications (VBA), Business Intelligence (BI), Data Cleaning
Technical Manager
1997 - 2007
Oracle
- Led the BI portal group by managing a team of ten consultants while being billable 100%. The team’s utilization was more than 90%. Actively involved in recruiting, training, resourcing, mentoring, and growing the team. Organized portal night classes and training and invited several key senior members to give talks.
- Implemented customer relationship modules (CRM) modules like iStore, iPayment, sales online, service contracts, XML gateway, and install base for clients like Canon, BMG, GE, and UBS.
- Managed onsite and offshore resources of up to 50 consultants on projects.
Technologies: Oracle Fusion Middleware, Oracle EBS, Java, Business Portals
Experience
AI-based Tutoring System
I was one of two developers who built an AI-based tutoring system that's currently being used in universities. This tutor helps students learn the subject using their topics of interest, so that student engagement is higher. Passages and dialogues are created with ChatGPT. I used ChatGPT to improve the prompts by feeding the student interactions.
Quality Assurance (aka Sherlock)
Pfizer has strict requirements to resolve all deviations within a certain time limit. Hence, the deviations are presented to users in a digestible manner, with similar deviations, past resolutions, and any corrective/preventive actions. To provide search capability across past deviations, Elasticsearch was implemented in a multi-language model for managing searches and results.
Reporting of Insurance Claims for Open Practice Solutions Customers
Open Practice has different databases for each of its clients. There was a need to build a consolidated reporting system, and hence, the data was brought into one Redshift database from several different source databases. I built the ETL to dynamically select data sources, tables, and columns so that any change in the data definitions does not have an impact on the ETL.
Web Application to Capture Students' Performance
Architected a web-based application for World Health Partners (India chapter) to be used by rural schools to enter students’ performance on quizzes. I designed the database objects and APIs from scratch to be used in the web application built with Python and Django and deployed in AWS. I also developed core APIs using Python, MySQL, and MongoDB databases.
Asset Data Migration
The client had over six million customers in their CRM system and half a million assets in the GIS system. I was responsible for migrating these customers and assets one time into the new asset management system and planning for syncing updates between the two systems.
-Oversaw and ensured delivery of all data analysis, mapping, and transfer aspects.
-Worked with program managers and business users to capture and analyze business requirements.
-Conducted gap analysis and developed data migration and integration plans.
-Oversaw and ensured delivery of all data analysis, mapping, and transfer aspects.
-Worked with program managers and business users to capture and analyze business requirements.
-Conducted gap analysis and developed data migration and integration plans.
Error Reporting of Failed Integrations
The client had several integrations—real-time, batch, and near real-time. Integrations fail either due to hardware issues or software glitches. Many times, it is hard for the source system to resend the data for failures. I built a semi-automated error-handling framework to reprocess failed transactions wherever possible. I also built reports with a drill-down feature to get to the bottom of the erroneous transaction for root-cause analysis. I developed a web application using Python, XML, and PL/SQL.
Education
1987 - 1989
ICWA (Master’s Degree Equivalent) in Cost Accounting
Institute of Cost and Works Accountants of India - Kolkata, India
1982 - 1984
Master of Science Degree in Applied Math
Anna University - Chennai, India
1978 - 1982
Bachelor of Science Degree in Mathematics
Madras University - Chennai, India
Certifications
MAY 2020 - PRESENT
Google Cloud Platform Fundamentals: Core Infrastructure
Coursera
MAY 2020 - PRESENT
Google Cloud Platform Big Data and Machine Learning Fundamentals
Coursera
OCTOBER 2005 - PRESENT
Oracle Database Administrator
Oracle Corporation
Skills
Libraries/APIs
REST APIs, React, Node.js, PySpark, Flask API
Tools
Oracle JDeveloper 12c, Oracle ERP, ELK (Elastic Stack), Elastic, AWS Step Functions, Microsoft Excel, JDeveloper, SAP Hybris, Informatica ETL, DataGrip, Atom, Splunk, Apache Airflow, Amazon QuickSight, Microsoft Visual Studio, Amazon WorkSpaces, Oracle E-Business Suite (EBS), NGINX
Languages
Python, SQL, Python 3, JavaScript, Snowflake, Bash, TypeScript, XQuery, R, Java, Visual Basic for Applications (VBA)
Paradigms
ETL, Database Design, Service-oriented Architecture (SOA), Business Intelligence (BI), HIPAA Compliance
Platforms
Linux, Oracle, Amazon Web Services (AWS), Unix, Windows, AWS Lambda, Oracle Database, Oracle Data Integrator (ODI), Kubernetes, Amazon Lightsail, Oracle Integration Cloud (OIC)
Storage
PostgreSQL, JSON, Data Pipelines, MySQL, Neo4j, Data Integration, MongoDB, Master Data Management (MDM), Redshift, Oracle SQL Developer, Amazon S3 (AWS S3)
Frameworks
Oracle ADF
Other
Data Architecture, Data Modeling, Oracle EBS, Oracle Fusion Middleware, Data Engineering, Data Visualization, Data Migration, APIs, ETL Pipelines, Data Cleaning, Large Data Sets, CSV File Processing, Enterprise Architecture, Integration, Data Science, Supabase, Cloud Infrastructure, Enterprise Data Warehouse (EDW), Fivetran, Dashboards, Data Build Tool (dbt), API Integration, Artificial Intelligence (AI), Systems Engineering, Reporting, eCommerce, Business Portals, Laboratory Information Management System (LIMS), Aerospace & Defense, Gunicorn, Prompt Engineering, ChatGPT API, AML, Agentic AI, Content Management Systems (CMS)
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