❯ About

Sakthivel Balasubramaniam (aka) Shakthi, a simple and curious human who loves building things that work well at scale. I’m passionate about clean code, system design, and the ever-evolving world of tech — always exploring, always learning.

Currently based in Amsterdam, writing software and wondering how things work under the hood.

LinkedIn • Github • Twitter • HackerRank • LeetCode • CodePen

Summary

Senior Software Engineer with 9+ years of experience in fintech, banking, and payment solutions, specializing in designing scalable distributed systems and seamless platform integrations. Known for independently driving complex technical initiatives, streamlining system performance, and delivering exceptional user experiences. Proficient in Java, Golang, and a wide array of modern frameworks, with a proven ability to rapidly learn and adapt to emerging technologies and industry trends.

I am a jovial, open-minded, and friendly individual who thrives in collaborative environments, building strong relationships with teammates, stakeholders, and clients. My positive attitude and approachability foster open communication and productive teamwork, enabling me to align diverse perspectives toward shared goals. A results-driven professional with a problem-solving mindset, I excel at transforming challenges into opportunities for innovation, improvement, and growth.

Passionate about creating secure, high-quality software solutions, I am dedicated to continuous learning, knowledge-sharing, and fostering an environment of mutual trust and innovation. My commitment to excellence and adaptability ensures I consistently deliver impactful results that exceed expectations.

Technical Skills

  • Languages: Java (8-21), Kotlin, Golang, Python, JavaScript, Bash
  • Frameworks: Spring Boot 3, Hibernate, JUnit 5, Gin, ReactJS, React Native
  • Architectures: Microservices, Event-driven, REST, GraphQL, gRPC, Protobuf
  • Databases: PostgreSQL, Oracle, MySQL, MSSQL, DynamoDB
  • Technologies: AWS, Docker, Kubernetes, Redis, Kafka, Jaeger, ELK Stack, Terraform
  • AI & Tooling: Claude Code, GitHub Copilot, LangChain, LangGraph, RAG Pipelines, MCP
  • DevOps & Tools: GitLab CI, GitHub CI, Jenkins, Maven, Gradle, Pact, Testcontainers
  • Practices: TDD, BDD, Clean Code, CI/CD, Contract Testing, Pair Programming
  • Collaboration: Agile/Scrum/Kanban, Mentoring, Sprint Planning, Code Reviews, Feature Ownership

Work Experience

Backbase, Amsterdam, Netherlands (Jul 2025 - Present)
Senior Backend Engineer

Digital Banking - Payments - a highly configurable, white-label core payment suite integrating multiple providers to process diverse, recurring, and scheduled payments.

Tech stack: Java 21, Spring Boot 3, Kafka, Oracle, Redis, GitHub CI, Argo CD, Docker, Kubernetes.

  • Engineered a high-throughput bulk payment feature within the core rule engine by introducing an event-driven architecture, enabling the concurrent processing of 10,000+ payments across diverse corridors (US domestic, international, SEPA).
  • Led backend File Import squad to deliver “Bulk Upload V2” - CSV/TSV-based payments in accelerated timeline, introducing capabilities like file previews, substitution rules & advanced error handling.
  • Standardized error-handling mechanisms across core payment services, significantly improving API reliability and providing richer debugging context for downstream consumers.
  • Accelerated developer ramp-up time by revamping backend onboarding processes up to date, breaking down knowledge silos with centralized documentation, and actively mentoring junior engineers.

Passionate People, Amsterdam, Netherlands (Jul 2022 - Jun 2025)
Senior Software Engineer (Consultant)

VodafoneZiggo [Checkout Squad] - developed rule engine and services to orchestrate purchase & catered products.

Tech stack: Java 21, Golang, Spring Boot 3, Gin, Kafka, Oracle, Redis, GitLab CI, Terraform, Docker, Kubernetes.

  • Engineered a high-performance rule engine to dynamically orchestrate product offerings, increasing personalized checkout experiences and reducing processing time.
  • Optimized core REST and GraphQL API and migrated legacy downstream systems, reducing latency by 40%, enhancing user experience, and delivered substantial cost savings for the business.
  • Migrated microservices to Java 21 & Spring Boot 3.3, achieving zero downtime and ensuring a seamless transition.
  • Revamped CI/CD pipelines by migrating from Jenkins to GitLab CI and adopting Terraform for infrastructure automation, boosting deployment consistency and developer productivity.
  • Applied Domain-Driven Design principles to model complex domains, collaborate with domain experts, and implement aggregates, value objects, and bounded contexts with business needs effectively.

Thoughtworks Technologies, Chennai, India (Nov 2018 - Jun 2022)
Senior Consultant – Application Developer

Payments squad - developed payments service for internet and mobile banking platform for India’s leading private bank.

Tech stack: Java 17+, Golang, Spring Boot, React, React Native, Oracle, Redis, Kafka, Docker, Contract testing.

  • Collaborated closely with product owners to develop solutions and technical designs, taking end-to-end ownership of various payment features with a strong focus on high-speed, high-volume solutions, performance and security.
  • Implemented a bulk payment system, enabling users to process thousands of scheduled payments concurrently by simply uploading an XLSX file, which resulted in 35% increase in business traffic.
  • Led the initiative to separate UPI-specific features into distinct microservices, overseeing the setup of CI/CD pipelines, test pyramids, permissions, database migrations, and ensuring backward compatibility.
  • Developed and implemented an end-to-end contract testing framework to streamline backward compatibility testing, reducing numerous hours and days of manual testing across various mobile app versions.
  • Developed secure APIs and authentication services, ensuring compliance with banking and regulatory standards similar to ISO 27001.
  • Proactively led tech grooming sessions, huddles, and discussions within the team and across squads in the absence of the Team Lead.
  • Actively self signed-up in on-boarding new team members, and presented technical workshops internally for knowledge transfer session and best coding practices with fellow engineers.
  • Developed various screen and components for both web and mobile.
  • Actively self signed in on-boarding new team members, took knowledge transfer session and shared my learning with team members.

Security Subsystem is a custom IAM for the first cloud-only bank in Spain.

Tech stack: Java, Spring Boot, Golang, Gin, ReactJS, Postgres, AWS DynamoDB, AWS RDS, Bamboo CI, microservices.

  • Developed a high-performance authentication service in Go, achieving a response time of 5ms.
  • Engineered advanced solutions within the risk engine to thwart service attacks and safeguard user credentials.
  • Developed an authorization service and session management system in Java to address complex regulatory requirements effectively.
  • Acquired extensive knowledge and hands-on experience in the security domain through the development of secure APIs.
  • Designed and executed a comprehensive mitigation plan to address QA resource shortages effectively.

Dhyan Networks and Technologies, Chennai, India (May 2016 - Nov 2018)
Software Engineer

Alpine Patrol provides major EMS functionality, which includes Fault, Configuration, Accounting, Performance and Security.

Tech stack: Java, Structs 2, EJB, JSP, DOJO JS, Postgres, Ant.

  • Spearheaded the graphical view enhancement to existing visualization feature, that represented data encapsulation in an Optical Fibre from 10GB to 100GB.
  • Designed and implemented a scalable data collection system and dashboard, increasing accuracy by 25% in high-volume environments.
  • Contributed to the design, development, and enhancement of various modules in Alpine Patrol, including REST services, GSCP adapter, dashboards, and graphical representations.

Skills

  • Fast learner
  • Open minded
  • Jovial
  • Problem solver
  • Agile
  • Collabator
  • Ice breaker

ACHIEVEMENTS

  • Developed and implemented a robust automation framework that reduced manual testing time by 70%, saving significant costs and improving overall efficiency.
  • Completed the Concurrency in GO on Coursera, gaining in-depth knowledge and practical skills in implementing concurrency in golang, verified through a comprehensive certification process.

EXTRA-CURRICULAR ACTIVITIES

  • Organized 30+ Geek Night Chennai, tech meetup for 3 years, sponsored by Thoughtworks India, fostering developer community and knowledge sharing.
  • Regularly conducted threat modeling sessions, improving application security and team awareness of potential risks.