Fatih A.

ACA Group is a global governance, risk, and compliance technology firm providing regulatory compliance and data analytics solutions to financial institutions.

• Designed and delivered a compliance-grade archival system processing over 200M emails (EML/PST files) using AWS Batch, Lambda, and Step Functions
• Built an event-sourcing and audit logging system handling 10M+ daily events through SNS, Kinesis, and S3 Iceberg tables for analytical querying
• Developed Java microservices with Spring Boot for ingestion, transformation, and reporting pipelines
• Implemented Athena partitioning and cost-optimized query models
• Automated deployment and infrastructure provisioning using AWS CDK, ensuring reproducibility

Optiva is a global telecom solutions provider delivering cloud-based OSS/BSS and monetization platforms for mobile operators.

• Designed and implemented data extraction and aggregation pods for high-frequency telecom billing systems using Quarkus and Kubernetes
• Built reporting servers and staging layers to support accurate, high-performance client reporting
• Developed logging sidecars for Kubernetes pods, standardizing observability and troubleshooting across deployments
• Led multiple complex integration and feature delivery projects, coordinating closely with product experts and client stakeholders

Sqills, now part of Siemens Mobility, develops S3 Passenger, a leading SaaS platform for rail and bus operators across Europe.

• Developed and optimized core modules for S3 Passenger, a SaaS platform used by over 30 major transport providers globally
• Refactored legacy modules and improved code quality, test coverage, and deployment reliability
• Applied Behavior-Driven Development (BDD) using Cucumber to ensure business alignment and test automation
• Researched and integrated modern frameworks (e.g., Quarkus, Micronaut) to improve performance and maintainability
• Proposed and implemented database optimization strategies, improving query performance by 25%

i2i Systems is a software company providing billing, CRM, and analytics solutions for telecom and utility providers.

• Designed and implemented a renewal module for recurring products, managing scheduled jobs and Kafka-based event messaging
• Developed recurring payment and taxation libraries, automating discount and pricing logic across multiple currencies
• Enhanced product lifecycle workflows by introducing modular and reusable backend components