About Sivasyam
As a Senior Software Engineer at Solarisbank AG, I bring over three years of experience in designing and optimizing scalable backend systems for fintech solutions. My work focuses on real-time card authorization and settlement processes, leveraging in-depth knowledge of ISO 8583 standards, Spring Boot, Microservices and AWS services like ECS, Lambda, and RDS. By collaborating with cross-functional teams, I contribute to delivering reliable and efficient payment infrastructure that supports Visa and Mastercard integrations.
Dedicated to advancing financial services, I specialize in building secure, high-performance backend infrastructure. My role emphasizes system reliability, robust error handling, and continuous improvement of development practices. Through innovation and teamwork, I aim to enhance the scalability and resilience of FinTech platforms while driving impactful solutions in the financial services domain.
English
Native or bilingual
German
Basic
Can work on-site
Berlin (up to 50km)
Experience
- Solarisbank SESenior Software Engineer | Cards & Payments | Agentic AIBANKING AND INSURANCEJanuary 2022 - Today (4 years and 6 months)Berlin, GermanyLeading backend development for card payment processing systems in a regulated Banking-as-a-Service environment.
- Leading core backend microservices development for mission-critical card payment processing and core authorization flows in a highly regulated Banking-as-a-Service (BaaS) ecosystem.
- Architected and integrated an Agentic AI feature into the internal back-office tool using LangChain4j, spring AI, and pgvector, allowing operations and audit teams to conduct complex semantic data queries and transaction analysis via natural language prompts.
- Utilized LLM function-calling capabilities to map back-office natural language queries safely onto secure internal REST endpoints, extracting real-time context for card lifecycle states (authorizations, disputes, chargebacks) deterministically.
- Resolved recurring production issues in the settlement process by redesigning the execution model from AWS Lambda to event-triggered ECS tasks, significantly improving platform reliability while keeping infrastructure costs optimized.
- Proposed and implemented automated test coverage enforcement using JaCoCo, integrating quality gates into CI/CD pipelines and failing builds when minimum thresholds were not met.
- Reduced infrastructure costs by migrating authorization and settlement data from DynamoDB to PostgreSQL (RDS), improving maintainability and aligning storage with transactional workloads.
- Designed and executed migration pipelines from DynamoDB streams into PostgreSQL-based architecture for a more efficient and cost-effective data platform.
- Built and enhanced REST APIs supporting card lifecycle flows including authorization, clearing, reconciliation, chargebacks, and dispute management.
- Improved observability through structured logging, tracing, and monitoring using CloudWatch and distributed tracing practices.
- Mentored junior engineers and promoted clean architecture, coding standards, and engineering best practices.
- HeycarSenior Backend EngineerOctober 2020 - December 2021 (1 year and 2 months)Berlin, Germany
- Developed backend services for marketplace and dealer integrations using Java, Kotlin, and Spring Boot.
- Designed microservices for finance and lead-partner services.
- Built integrations with external financial partners and dealer platforms.
- Worked with AWS services including EKS, SQS, S3, Firehose, and EC2.
- Contributed to architecture decisions, CI/CD processes, and production support.
- Provided technical mentoring and code reviews to team members.
- Bonify GermanyBackend developerJuly 2018 - September 2020 (2 years and 2 months)Berlin, Germany• Backend Developer working with cross-functional team to develop and maintain bank-connector, partner-connector and scoring service• Developed microservices using java and spring boot• Worked on distributed version control system like Git and Source Tree for GUI• Worked on build tool in Maven and Gradle• Worked on Message broker like RabbitMQ• Integration of bank partner APIs• Successfully implemented PSD2 API changes• Responsible for development to deployment, including troubleshooting and production fixes• Reviewing code written by the team and provide the review comments
Recommendations
Be the first to recommend Sivasyam
Help this freelancer shine by sharing your experience working together.
These freelancer profiles also match your criteria
Agatha Frydrych
Backend Java Software Engineer
4.7
(3)
2
Baptiste Duhen
Fullstack developer
4.6
(4)
5
Amed Hamou
Senior Lead Developer
4
(2)
7
Audrey Champion
Web developer
4.3
(3)
4
Education
- MCAIndira Gandhi National Open University2009MCA
- Bachelor of Science - BSAcharya Nagarjuna University2005Bachelor of Science - BS