Mateusz Gajewski

Led cloud and deployment modernization for 16 production services using Kubernetes, AWS, Terraform, and Docker. Migrated 14 workloads to Amazon EKS, implementing Kubernetes deployments, autoscaling, health checks, and resilient rollout controls. Built 12 reusable Terraform modules for repeatable AWS environments (networking, compute, databases, service configuration, and deployment dependencies). Automated 18 CI/CD workflows using GitHub pipelines, Docker images, automated validation, deployment gates, and repeatable production release practices. Improved observability across 20 services using OpenTelemetry, Prometheus, Grafana, structured logging, and distributed tracing. Increased reliability for 11 critical services by adding timeouts, retries, circuit breakers, health checks, graceful degradation, and incident-focused root-cause analysis. Standardized containerized development and deployment workflows across 24 engineering tasks, mentoring 5 engineers and contributing to architect

Designed and developed Java and Kotlin microservices for a multi-tenant SaaS platform serving 2M+ monthly users. Built REST and gRPC APIs using Spring Boot with API contracts, validation, authentication, and backward-compatible practices. Modernized legacy batch processing into Kafka-based asynchronous services, reducing processing time from 4.5 hours to 48 minutes. Improved PostgreSQL performance via schema design, indexing strategies, query optimization, partitioning, and transaction tuning. Introduced Redis caching strategies that reduced database traffic by 61% and improved application responsiveness. Designed and maintained AWS infrastructure with ECS, RDS, Lambda, S3, SQS, IAM, and Terraform. Enhanced software delivery using Jenkins and GitHub Actions automation, enabling multiple production deployments per day. Participated in architecture decisions, production support, incident reviews, code reviews, and technical mentoring.

Developed Java and Spring Boot backend services supporting enterprise customer-management and billing platforms. Designed REST APIs and backend integrations consumed by internal applications and external enterprise systems. Improved database performance through PostgreSQL schema design, indexing strategies, SQL optimization, and query tuning. Introduced synchronous processing using RabbitMQ to reduce service coupling and improve responsiveness. Containerized applications with Docker and standardized development environments across engineering teams. Improved software quality with automated testing (JUnit and Mockito) and automated development/deployment workflows, reducing manual release activities by ~40%. Contributed to technical design discussions, code reviews, production troubleshooting, and Agile delivery.