harshil harshil

• Designed a middleware server to address the issue of storing complete communication between a service provider and service user, due to the service provider's system's database being unable to handle the increasing load. • Utilized MongoDB as a clustered database for storing the requests sent by the service user on the middleware server, as well as storing the webhook from the service provider. • Implemented a solution to store the webhook data in the middleware server and also send it to the service user, ensuring seamless communication between both parties. • Provided a reliable and scalable solution for storing transaction data, allowing service users to probe the transaction status in the future using the middleware server. • Addressed the urgency of deployment by designing and implementing the middleware server promptly, as understanding the complexities of the existing system would have taken more time. • Ensured data integrity and security by utilizing a clustered database and implementing appropriate data storage practices in the middleware server. • Collaborated with the service provider and service user teams to understand their requirements and ensure seamless integration of the middleware server into their existing systems. • Implemented proper error handling and logging mechanisms in the middleware server to track and diagnose any issues related to communication and data storage. • Demonstrated technical expertise in designing and implementing a middleware server that acted as an intermediate layer between the service provider and service user systems. • Played a critical role in improving the overall system performance by designing and implementing the middleware server, which successfully stored and managed transaction data, mitigating the limitations of the existing system's database.

• Collaborated with a team to develop a payment gateway in Java, utilizing microservice architecture for scalability and flexibility. • Implemented Agile methodologies using Jira and 1-week Scrum concept to efficiently manage project tasks and avoid backlogs, ensuring timely completion. • Utilized MySQL and MongoDB databases for data storage and retrieval, ensuring efficient and secure handling of payment-related information. • Worked on the backend side, creating APIs for merchant registration and other essential features, ensuring smooth integration with the frontend. • Developed APIs for various payment-related functionalities such as processing payments, handling refunds, and managing transactions securely and efficiently. • Implemented merchant registration functionality, allowing merchants to register and onboard onto the payment gateway platform seamlessly. • Collaborated with the frontend team using React, ensuring seamless integration of backend APIs with the user interface. • Ensured code quality and adherence to best practices, including proper error handling, input validation, and data security measures. • Worked closely with other team members, including frontend developers, database administrators, and QA team, to ensure smooth project execution and timely delivery. • Contributed to the overall success of the project by actively participating in team discussions, providing technical expertise, and delivering high-quality backend solutions for the payment gateway system.

• Developed a payment gateway from scratch using Node.js as backend, MySQL and MongoDB for databases, and ArangoDB for switching, designed with monolithic architecture with future scalability to microservices in mind. • Implemented merchant and admin panels to provide comprehensive control and monitoring of the payment gateway system. • Added load balancing to bank APIs to distribute payment request load and prevent overload on a single bank, with configurable settings from the admin panel for easy control. • Implemented a smart router to switch bank pipelines from one to another in case of downtime, ensuring high availability and uninterrupted service. • Designed the system to comply with PCIDSS (Payment Card Industry Data Security Standard) norms, ensuring security and protection of sensitive payment information. • Documented all aspects of the system for SAR (System Audit Report) compliance, maintaining a comprehensive record for auditing and security purposes. • Added auto-reconciliation feature to match bank transaction data with the system's database, confirming successful payouts and pay-ins for accurate accounting. • Implemented blacklisting features to block suspicious or unauthorized activities such as UPI, cards, netbanking, phone numbers, IP addresses, etc., enhancing security measures. • Developed onboarding feature for seamless onboarding of new merchants, simplifying the process of adding new partners to the payment gateway system. • Added notification feature to alert for loss whenever the cost of a pipeline exceeds the cost of merchant service, allowing for timely cancellation or rejection of transactions to minimize losses and prevent downtime. All features were configurable from the admin dashboard, providing flexibility and control over the payment gateway system.

• Designed stateless servers for secure API communication between API users and API providers. • Deployed the servers on AWS, implementing security measures and a CI/CD pipeline with GitHub for updates. • Utilized a load balancer to upscale on demand, ensuring no downtime and optimal request serving. • Created a cost-effective solution by avoiding the use of any database, reducing deployment costs. • Implemented security measures to ensure the privacy of both API providers and users. • Managed the AWS deployment, including server setup, configuration, and monitoring. • Implemented a scalable architecture that can dynamically adjust to traffic demands. • Maintained high availability and performance of the API communication system. • Ensured continuous integration and deployment for seamless updates and improvements. • Monitored and optimized server performance, cost, and security to maintain efficient operations.

• Designed and deployed a mailing server from scratch, without the use of any relay, ensuring end- to-end email communication. • Implemented a bare metal deployment using Proxmox on the hardware, followed by Debian installation and configuration for the mailing server. • Configured Anti-Virus (AV) scanner for scanning incoming documents to ensure security and prevent malware. • Managed DNS settings, including SPF, DKIM, DMARC, and PTR records, to ensure smooth functioning of the mail server and enhance security. • Implemented AV relay on the mailing server itself for efficient mail delivery and receipt. • Ensured seamless communication of mails by optimizing the server for low-latency and high reliability. • Implemented security best practices, including regular security patches, updates, and configuration hardening. • Maintained documentation and backups for disaster recovery and business continuity. • Provided technical support and troubleshooting for any issues related to the mailing server, DNS, and other related components.

• Worked with NASA on a project to create a low-latency rocket propulsion system. • Helped design and code for a hardware embedded chip with limited memory and space. • Developed a synchronized method for 4 different systems to display the same sensor data. • Implemented a proton bit switcher to maintain data integrity. • Collaborated with a team to ensure all functionalities were preserved in the embedded system. • Ensured the code was optimized to fit within the limited resources of the hardware. • Worked on maintaining low latency performance for critical rocket propulsion system. • Managed the challenges of coding for an embedded system with limited memory and space while maintaining data integrity and synchronization among multiple systems.