JANHAVI PAWAR

Backend Development (Java, Spring Boot, REST, SOAP) Microservices Architecture & Enterprise Integrations Application Modernization & Legacy System Migration E-lnvoicing & Payment Processing Platforms

Database Design, SQL Optimization & Stored Procedures Performance Optimization & Scalability Engineering

PCI DSS & Security Compliance (Passwords, Encryption, Access) Production Support, Debugging & Root Cause Analysis

Code Reviews, Clean Code & Design Patterns

Server Upgrades & Environment Management (Tomcat, WildFly, JDK) Agile SDLC & Cross-Functional Collaboration

Logging, Monitoring & Audit Trail Implementation

Programming

Java: Core Java, Advanced Java,

SQL

Spring Boot Hibernate / JPA JDBC, Swing

Angular (basic)

Backend Technologies

REST API, SOAP Web Services

JSON, XML

Microservices

File processing, CSV export, report generation Database

Stored Procedures Query Optimization Database Design

Tools

Git, Maven Postman, lntelliJ IDEA, Eclipse

Servers

Apache Tomcat WildFly {JBoss)

Methodologies & Practices Agile {Scrum)

Debugging & Root Cause Analysis Production Support (L2/L3)

Security Compliance (PCI DSS, password policies, encryption)

September 2021- Present

Product company in retail and payment solutions (POS, e-invoicing, payment processing, enterprise integrations).

Designed and implemented Malaysia e-lnvoice backend services using Core Java, Spring Boot, REST API, Hibernate, MSSQL, enabling compliant e-invoice generation, validation, and submission to government systems and reducing manual compliance effort for customers.

Migrated key enterprise integrations from SOAP web services to RESTful API using Java, Spring, JSON/XML, improving API performance and scalability by ~30% and significantly simplifying maintenance.

Architected and delivered a Bill Cancellation module using Java, JDBC, MSSQL with transactional integrity checks and audit logging, minimizing billing inconsistencies and improving traceability for finance and audit teams.

Implemented an E-Journal report module using Java file processing and MSSQL, archiving all POS transaction logs into structured files, strengthening compliance and enabling faster investigation for disputes and audits.

Built backend services for Digital Receipts using Java, REST API, JSON, integrating POS transaction data with external channels for seamless e-receipt delivery and full audit trails.

Developed and optimized a Stock document upload module using Java, JDBC, MSSQL, improving bulk stock data ingestion throughput by ~40% and reducing upload failures for large retail clients.

Implemented CSV export utilities for backend-generated reports using Java, CSV processing, MSSQL, enabling dynamic filtering and multi-format export for operations and finance reporting.

Modernized application stack through JDK migration from Java 8 to Java 17 and application server upgrades for Apache Tomcat and WildFly, planning and executing changes with zero production downtime.

Engineered PCI DSS-compliant security controls using Java and encryption libraries, including 12-character password policies, strength validation, password encryption, and CRC utility checks, closing critical security gaps and passing PCI security audits.

Resolved complex PCI payment processing issues using Java, JDBC, MSSQL, ensuring secure transaction flows and restoring full PCI DSS compliance for payment modules.

Enhanced ETP Connect backend using Hibernate/JPA, JDBC, JSP integrations, optimizing queries and ORM mappings to improve page load times and system responsiveness.

Implemented POS hotkeys functionality in backend flows using Core Java and existing service layers, improving cashier efficiency and reducing average transaction handling time.

Strengthened transaction logging and audit trails using Java, file 1/0, JSON/XML, centralizing logs for payment, e-invoice, and receipt workflows, which reduced mean time to resolve (MTTR) production issues.

Diagnosed and fixed high-severity production incidents across e-invoicing, POS, and payment services using Java debugging, log analysis, SQL profiling, improving system stability and reducing recurring incidents.

Performed code reviews for Java and Spring Boot services, enforcing best practices on exception handling, design patterns, and performance, which improved code quality and reduced defects in QA and production.

Guided and mentored junior developers and freshers on Core Java, REST API, Hibernate, SQL, and debugging practices, accelerating team onboarding and overall delivery velocity.

Collaborated with frontend, QA, DevOps, and product teams in an Agile environment, driving end-to-end delivery of backend features and production fixes within sprint timelines.

Applied vendor security patches and performed backend updates on Java, libraries, and servers, mitigating vulnerabilities and maintaining platform stability.

KEY RESPONSIBILITY PROJECTS:-

MALAYSIA E-INVOICE PLATFORM:

Role: JAVA DEVELOPER

Tech Stack: Java, Spring Boot, REST API, Hibernate/JPA, JDBC, MSSQL, JSON, XML, Apache Tomcat

Designed and implemented e-invoice generation and lifecycle management using Java, Spring Boot, Hibernate, MSSQL, supporting creation, validation, and submission of invoices aligned with Malaysia government standards.

Developed REST API endpoints using Spring Boot and JSON/XML for invoice creation, status retrieval, and cancellation, enabling seamless integration with POS and ERP systems.

Implemented business validation rules in Core Java for tax calculations, mandatory fields, invoice formats, and government schema compliance, reducing invoice rejection rates.

Integrated with government e-invoicing systems using REST APIand secure communication, ensuring compliance with regulatory timelines and response handling.

Built robust audit logging using Java and database/file logging, capturing every invoice event (creation, modification, cancellation, submission, response), improving traceability for finance and statutory audits.

Optimized database queries and indexing in MSSQL for invoice storage and retrieval, reducing response time and improving throughput for high transaction volumes.

DIGITAL RECEIPT SERVICE:

Role: JAVA DEVELOPER

Tech Stack: Java, REST API, JSON, JDBC, MSSQL, Apache Tomcat

Implemented a Digital Receipt generation service using Java and REST API, transforming POS transaction data into digital receipts for email/SMS delivery.

Integrated backend receipt workflows with POS and external communication systems using

JSON over REST, ensuring accurate and timely delivery of customer receipts.

Ensured idempotent and reliable receipt generation using transaction management (JDBC/MSSQL) to avoid duplicate receipts and maintain financial accuracy.

Added detailed logging and audit data for receipt events in MSSQL and log files, enabling easy traceability of receipts during customer support and dispute resolution.

E-JOURNAL ARCHIVAL MODULE

Role: JAVA DEVELOPER

Tech Stack: Java, File Processing, JDBC, MSSQL, CSV/Text

Engineered an E-Journal module using Core Java file processing to periodically capture and archive all POS transaction logs in structured files.

Designed the data model and extraction logic using JDBC and MSSQL, ensuring complete coverage of transaction attributes required for audit and legal compliance.

Implemented configurable archival schedules and file rotation strategies, balancing disk usage and retrieval performance for large enterprise deployments.

Enabled audit tracking and compliance reporting by generating structured E-Journal outputs that could be consumed by downstream reporting and compliance tools.

PCI DSS COMPLIANCE

Role: JAVA DEVELOPER

Tech Stack: Java, Security API, JDBC, MSSQL, WildFly/Tomcat

Implemented PCI DSS-aligned password policies using Core Java, enforcing minimum length, complexity, and expiry rules for SSF and POS backend users.

Integrated password encryption and secure storage using Java encryption libraries and MSSQL, ensuring that sensitive credentials were never stored or transmitted in plain text.

Developed and integrated a CRC Utility check module using Java, adding integrity checks for critical payment data and configurations to prevent tampering.

Collaborated with security and compliance teams to address PCI vulnerabilities, patching insecure cryptographic usages and tightening access controls at the application layer.

Validated payment workflows end-to-end for PCI compliance, fixing backend issues in Java, JDBC, MSSQL, which enabled successful PCI audits and reduced security risk exposure.