Sai Krishna Reddy Chityala

FIS Clearing PIM

• It is a REST API that handles clearing of Authorized Transactions that are processed by FIS IST Switch.
• API reads all transactions from database and send them in CSV file to FIS for clearing.
• API communicates with FIS over Kafka on the status of Transaction sent for clearing.
• Implemented in Java using Spring Boot (Uses Apache Kafka)
• App runs on AWS EKS

Klarna APM

• It is an alternative payment method for merchants
• Merchant can accept either from Terminal or on Ecommerce websites
• Klarna Ecommerce Service handles requests from Ecommerce
• Klarna Service handles requests from Terminal
• Implemented in Java using Spring Boot
• App runs on AWS EKS

Worldpay Settlement PIM

• Settlement PIM is batch job which settles money for the Worldpay merchants.
• App was running on On premises
• Migrated to AWS EKS (Involved in vulnerability remediation, code refactoring, writing Docker files, Hashicorp vault Integration, AWS SES for mail service).

Business Event Notifications

• It is an event driven microservice, which has following components
• Event-publisher: Picks events from database and publishes to Kafka.
• Event-Listener: Listens to Kafka for new events and creates notifications for corresponding subscribers and publishes notifications to Kafka.
• Notification Listener: Listens to notifications and sends the notification details to subscriber.
• Implemented in Java using Spring Boot (Uses Apache Kafka)
• App runs on AWS EKS

Monitoring Spring Boot Apps (On premise)

• Implemented Monitoring for spring boot apps running in on premise servers using Spring Boot Admin.

• Undergone training on Business domain.

Merchant Wallet

• It is a message-driven architectural based project to credit some percentage of settled transaction money to wallet
• When merchant opt ins for wallet, a trigger will be generated in database and event details will be sent to MQ.
• Event Listener takes event from MQ and publish notification to MQ.
• Notification Listener app takes notification and get subscriber details from database and calls corresponding subscriber to create merchant wallet.

Settlement Holds

• It is a spring batch which is scheduled to run every day to create hold on authorized transactions.
• It must call external REST service to create hold
• So, to increase the performance, records from database are partitioned and processed in multiple executors based on thread pool size and number of records to process.

Card Exclusions

• It is a REST API which provides user to exclude his card number from being blocked when something fraud happens.

Transaction Research

• It is a REST API that provides merchant to check business details like transaction amount, settlement amount, reject amount and transaction details like card network, transaction date time.