Oleksandr M.

I'm a Java/Spring Boot developer with 6 years of experience across CRM, loyalty, and B2B platforms. I work independently from requirements to production — database design, business logic, tests, CI/CD — and I take responsibility for backend features, not just closing tickets. Top Rated on Upwork with $10K+ earned across 25+ contracts and 600+ hours. 5.0-rated and tagged "Clear Communicator" by 5 clients. What I've done recently: ▪️ Performance: On a CRM for a French solar-installation company, I rebuilt the MongoDB query and indexing strategy and cut execution times by 10x+ across reporting, analytics, and core workflows. ▪️ Features to production: Implemented an AI-powered CRM analytics service from concept to production, including the GitHub Actions CI/CD pipeline that deploys it. Worked directly with stakeholders, without step-by-step supervision. ▪️ Integrations & automation: OAuth2 SSO so partner dashboards open with one click from inside the CRM, MSFT & Google Calendar sync, Kafka producers/consumers for async CRM events, plus a scheduled pipeline that pulls, deduplicates, and standardizes data from a public API with zero manual cleanup. ▪️ Existing codebases: Converted a legacy JSP server to a clean JSON REST API for mobile. I'm comfortable joining code I didn't write, figuring it out, and shipping new features without breaking what works. Stack: Java 8/11/17/21, Spring Boot, Spring Security, Spring Data JPA, Hibernate, REST / OpenAPI, PostgreSQL / MySQL, MongoDB, Apache Kafka, JUnit / Mockito / Testcontainers, Docker, Maven, Git, GitHub Actions I fit best for: • SaaS & CRM backends, B2B platforms • REST APIs and backend services from scratch or on top of existing code • Integrations: OAuth2, calendars, 3rd-party APIs, Kafka events • Slow backends: Postgres / Mongo tuning and refactoring How I work: clear daily updates, questions early instead of guesses, code with tests, Dockerized setup so you can run it in one command.