Barun Bhattacharjee — Senior Software Engineer

Seasoned Engineer with 14+ years of experience in Fintech, SaaS, and payment platforms, driving large-scale cloud-native systems, microservices architectures, and PCI DSS-compliant high-availability platforms. Expertise in AI/ML, Generative AI, automation, performance engineering, and test optimization, with a proven record of modernizing legacy systems, reducing development cycles, and enhancing enterprise-scale reliability. At VISA, leading Open Visa Net, a modern payment platform replacing legacy VisaNet systems. Integrated LLMs (OpenAI, Anthropic) for code generation, automated test case creation, and debugging, cutting development cycles by ~30%. Heading data migration programs to synchronize legacy and modern networks, and driving automation initiatives to ensure reliable financial and non-financial transaction processing for downstream partners. In Visa Platform & Core Engineering, led performance engineering across 15+ enterprise projects. Designed and implemented frameworks and pipelines to optimize system response times by 25%, automate 80% of regression and performance tests, and resolve 50+ critical bottlenecks. Collaborated with cross-functional teams, integrating Docker, Kubernetes, and CI/CD pipelines, improving scalability and reliability by 30%, and ensuring Tier-0 services with near-zero downtime. At ThoughtWorks, built scalable automation frameworks in Java and Python for clients like Kroger, Credit Suisse, and McKinsey, increasing test coverage by 45% and reducing manual testing efforts by 60%. At IBM, led automation and performance improvements for Sprint Telecom, cutting execution time by 35% and reducing production defect leakage by 15%. Technical expertise includes: Java, Python, SQL; AWS, Docker, Kubernetes; Microservices & API Gateway; Automation & Performance Testing (Selenium, TestNG, REST Assured, Postman, JMeter, Gatling); AI/ML & Generative AI integration; PCI DSS, API Security; TDD, BDD; Agile methodologies; CI/CD pipelines; high-availability and cloud-native systems. Passionate about embedding AI-driven innovation, mentoring teams, and delivering scalable, resilient, secure solutions. Experienced in AI-first fintech practices, including automated testing, monitoring, fraud detection workflows, and SaaS product lifecycle optimization. Awards include Star Performer (2021) at VISA for Push-Portal delivery, and GBS–GDS Eminence & Excellence Award (2012) at IBM.

Stackforce AI infers this person is a Fintech expert specializing in cloud-native systems and automation.

Location: Bengaluru, Karnataka, India

Experience: 14 yrs 10 mos

Skills

Performance Engineering
Test Automation
Cloud-native Systems
Microservices Architecture
Quality Assurance
Software Testing

Career Highlights

14+ years in Fintech and SaaS engineering.
Led automation initiatives reducing development cycles by ~30%.
Achieved 99.9999% uptime for complex distributed applications.

Work Experience

Visa

Staff Software Engineer (1 yr)

Senior Software Engineer (7 yrs 1 mo)

ThoughtWorks

QA Engineer (2 yrs 4 mos)

IBM India Private Limited

Senior System Engineer (4 yrs 5 mos)

Education

EPGP Machine Learning and Artificial Intelligence at International Institute of Information Technology Bangalore

PROFESSIONAL CERTIFICATE PROGRAM IN FINTECH at SP Jain School of Global Management - Dubai, Mumbai, Singapore & Sydney

Master of Computer Applications (M.C.A.) at National Institute of Technology, Jamshedpur

Bachelor of Commerce (B.Com.) at Vinoba Bhave University

Barun Bhattacharjee

Senior Software Engineer

Bengaluru, Karnataka, India14 yrs 10 mos experience

Most Likely To SwitchAI ML Practitioner

Key Highlights

14+ years in Fintech and SaaS engineering.
Led automation initiatives reducing development cycles by ~30%.
Achieved 99.9999% uptime for complex distributed applications.

Stackforce AI infers this person is a Fintech expert specializing in cloud-native systems and automation.

Contact

Skills

Core Skills

Performance EngineeringTest AutomationCloud-native SystemsMicroservices ArchitectureQuality AssuranceSoftware Testing

Other Skills

AI/ML IntegrationAPI TestingAgile MethodologiesAmazon Web Services (AWS)ArchitectureAutomated Test ScriptsAutomationAutomation TestingCICD PipelinesCTFLCheckoutsCommunicationContinuous IntegrationCore JavaData Migration

About

Experience

14 yrs 10 mos

Total Experience

4 yrs 11 mos

Average Tenure

8 yrs 1 mo

Current Experience

Visa

2 roles

Staff Software Engineer

Jun 2025 – Present · 1 yr

Senior Software Engineer

May 2018 – Jun 2025 · 7 yrs 1 mo

1. Orchestrated testing initiatives to achieve a 99.9999% uptime for a complex distributed application, handling a transaction volume of approximately 770 million.
2. Successfully delivered products across multiple releases with zero high-priority security findings with shift left mindset.
3. Executed rigorous testing and certification processes for various components, including Cache Providers, Rate Limiters, Resiliency Frameworks, Retry and Circuit Breaker implementations, Configuration Toggles, Feature Toggles, Platform Computation Service, Common Application Logging and Error Service, Data Access Layer, and Secure Access Layer adhering to VISA platform engineering standards.
4. Designed, developed, and sustained a Resilient Testing Framework for VISA Platform Libraries and Microservices, minimizing the impact of application code changes on the test framework at different test pyramid layers and test infrastructure.
5. For Test Infrastructure, build sample Spring Boot Application to test and Certify the Platform Library components.
6. Developed and implemented CICD pipelines and Regression Pipelines using Jenkins.
7. Delivered releases twice a month, individual releases for the VISA Platform components.
8. Triaging, Debugging and Troubleshooting the issues faced during integration of Platform component with other VISA Internal or External Applications.
9. Build JMeter Test Suite, for components which is getting build from Scratch under Platform initiatives as in Shift Left initiative.
10. Worked for businesses on Tokenization, Checkouts, SRC, Installments, Regional Banks Requirements and Mandates.
11. Awarded Star Performer in the Year 2021, for delivering Push-Portal and take it to production. It was helping OPS team with daily deployments and patching.
12. Recognized by Architect and Director of Engineering for showcasing End to End testing of Retry and Circuit Breaker library.

Testing InitiativesResilient Testing FrameworkCICD PipelinesJMeter Test SuiteTokenizationCheckouts+2

Thoughtworks

QA Engineer

Dec 2015 – Apr 2018 · 2 yrs 4 mos · Bengaluru Area, India

1) Give inputs on estimation of tasks broken down to smaller sub task
2) Create a test execution plan / strategy for a low – high complexity
application
3) Understand the business need and give independent inputs on the testing strategy.
4) Investigation, troubleshooting and root cause analysis of issues found to resolution.
5) Write, maintain and execute automated test scripts through software
product upgrades.
6) In-depth failure analysis performed against automated test executions.

Test Execution PlanAutomated Test ScriptsTroubleshootingRoot Cause AnalysisTest AutomationQuality Assurance

Ibm india private limited

Senior System Engineer

Jun 2011 – Nov 2015 · 4 yrs 5 mos · Bengaluru Area, India

1) Give oversight to a small team during test case creation and execution and ensure that team is adhering to processes.
2) Worked with the development team to understand how changes in the software product affect maintenance of test scripts and the QA automated testing environments.
3) Log different types of defects including core functionality, UI, database related defects and follow up on outstanding defects to determine the impact on release.

Test Case CreationDefect LoggingQA Automated TestingQuality AssuranceSoftware Testing