Ramdane Oualitsen

Migrated 2 microservices to Java 21 / Spring Boot 3 with virtual threads (Project Loom); benchmarks on real pre-production data showed ~3× throughput increase, ~50% memory reduction, and a ~70% drop in HTTP timeout errors under high concurrency Led backend microservice development and Angular frontend interfaces for a contact & campaign management platform Drove architecture decisions on microservice decomposition: defined service boundaries, ownership, and inter-service communication patterns across the platform Architected the migration from scheduled Spring Batch jobs to real-time Kafka event-driven pipelines, eliminating processing delays and decoupling producers from consumers Introduced a Redis cache layer to reduce database pressure; benchmarks showed ~1.8× improvement in response time and over 3× throughput gain under load Designed and operated multi-cloud infrastructure (AWS + GCP) with Kubernetes, Helm, and Jenkins CI/CD pipelines Developed a reference data microservice in Kotlin / Spring Boot responsible for exposing static references (search filters, enumerations, lookup values) consumed across the platform Introduced circuit breaker and retry patterns between microservices to improve resilience and prevent cascading failures under load Drove migration from session-based authentication to JWT, making services fully stateless and enabling safe horizontal scaling on Kubernetes Standardised observability across environments: structured JSON logs on integration, pre-production, and production for easy Grafana filtering; kept human-readable logs on local via Spring profiles for developer ergonomics Secured the platform with Spring Security, OpenID Connect (OAuth2), and Keycloak; managed SSL with CertManager / Let's Encrypt Designed performance test scenarios and monitored production with Grafana Enforced code quality through SonarQube Quality Gates, TDD/BDD, pair programming, and structured code reviews Managed database schema versioning with Flyway; documented APIs with Swagger

Open-source GraphQL code generation CLI (Dart) inspired by Retrofit and OpenFeign. Reads a .graphql schema and generates fully type-safe, production-ready code for Dart/Flutter clients, TypeScript clients and servers, Java clients, and Spring Boot (MVC & WebFlux) servers — eliminating DTOs, serializers, query strings, and HTTP wiring entirely. 72% of Spring Boot files and 64% of lines are generated in production — only 135 files (~11.8k lines) hand-written across an entire backend 21.5% of a full Flutter codebase is generated, covering all models, inputs, enums, and GraphQL client wiring Zero runtime dependency — generated code ships standalone with no lock-in to GraphLink No generics at the Java call site — unlike Apollo/standard clients requiring TypeReference<GraphQLResponse<T>> on every call Built-in caching via schema directives (@glCache, @glCacheInvalidate) with tag-based invalidation and offline fallback Production-proven in a large multi-tenant SaaS platform (dialysis clinic management)

Context: Developed and maintained a visual similarity recommendation engine for one of the world's largest luxury e-commerce platforms, serving millions of shoppers across Yoox, Net-A-Porter, Mr Porter, and The Outnet. Built the backend of a visual similarity recommendation system: image upload pipeline -> conversion to vector embeddings → indexing into Elasticsearch for real-time visual product search Designed and maintained backend microservices with Spring Boot, Spring Batch, PostgreSQL, and Elasticsearch Secured APIs with Spring Security & SAML authentication Migrated log infrastructure from AWS CloudWatch to Kinesis for cost reduction and improved observability Provisioned and managed AWS infrastructure with Terraform; configured remote state backend using S3 with DynamoDB-based state locking Managed secrets securely using HashiCorp Vault integrated with Terraform Created and maintained Jenkins CI/CD pipelines for build, test, and deployment automation Deployed and operated services on AWS Elastic Beanstalk with Jenkins CI/CD and Docker Applied TDD/BDD, Clean Code, and pair programming across a distributed international team

Designed and built a full-stack savings account management platform (employee savings / épargne salariale) from requirements to production deployment. Designed and built REST services with Spring Boot for core financial operations: subscriptions, deposits, transfers, and account closure Implemented Angular frontend with dynamic components, complex reactive forms, and client-side validation Secured the application with Spring Security (JWT authentication, role-based access management) Integrated external partner APIs and banking data flows Drove quality with JUnit/Mockito tests, SonarQube analysis, and Agile ceremonies (daily, reviews, retrospectives) Deployed continuously via Jenkins and monitored releases across test and production environments

- Development of graphical interfaces with AngularJS / Angular. - Development of the client and driver mobile application (Android). - Writing unit and integration tests. - Integration of payments using Stripe. - Integration of the Google Places API for address autocomplete. - SMS authentication via Google Firebase. - Implementation of Google Distance Matrix to calculate the distance with traffic between point A and point B. - Implementation of a cache for Google APIs to reduce costs. - Integration of Google Firebase for notifications. - Indexing with Elasticsearch for optimized search. - Creation of a background service using WebSocket for real-time event listening.