# Maksym Lisovyi — Backend & Full-Stack Engineer

> Results-driven Backend and Full-Stack Engineer (M.Sc. in Computer Science) specializing in high-concurrency ERP/CRM architectures, transactional database integrity, and scalable web systems using Modern PHP (8.5), Laravel 12+, FrankenPHP Octane, Vue 3, and TypeScript.

This portfolio documents production case studies, system architecture blueprints, and technical implementations built by Maksym Lisovyi. Key areas of expertise include database concurrency control (pessimistic locking and idempotency guarantees), pipeline architecture, OSRM GIS routing integration, long-running worker runtimes (FrankenPHP Octane), hardware scanner interception, and end-to-end type safety.

## Production Case Studies

- [Logistics CRM](https://lisovyi.me/projects/logistics-crm): High-concurrency B2B freight dispatching platform. Implements pessimistic row locking (lockForUpdate) to eliminate double-booking race conditions during simultaneous dispatch, dynamic rate calculation pipeline adhering to SOLID Open/Closed principle, OSRM GIS distance matrix with Redis caching, and real-time status broadcasting via Laravel Reverb WebSockets.
- [GymControl CRM & POS](https://lisovyi.me/projects/gym-control): High-performance fitness club management CRM and POS engine. Built for FrankenPHP Octane worker mode runtime with automated reflection leak prevention, sub-50ms hardware HID scanner buffer parsing, idempotent mutation guards via X-Operation-Key with Redis mutex locks, and FIDO2 WebAuthn biometric passkey authentication.

## Technical Stack & Standards

- [Architecture & Concurrency](https://lisovyi.me/#skills): Modern PHP 8.5, Laravel 12/13, Single-Action Pattern (app/Actions), Pipeline Architecture, Pessimistic Locking (lockForUpdate), Mutex Locks, Idempotent APIs.
- [Runtimes & Performance](https://lisovyi.me/#skills): FrankenPHP Octane worker lifecycle, stateless service design, Redis asynchronous queues, Laravel Reverb WebSockets, MinIO (S3) object storage.
- [Frontend & Type Safety](https://lisovyi.me/#skills): Vue 3.5, Strict TypeScript, Laravel Wayfinder (type-safe RPC and routes), Inertia.js SPA architecture, Tailwind CSS v4.
- [Testing & Quality Assurance](https://lisovyi.me/#skills): Pest PHP (coverage gates and architectural tests), strict static analysis (PHPStan Level 5+), FIDO2 WebAuthn Passkeys, Docker multi-stage containers, GitHub Actions CI/CD.

## Developer Profile & Contact

- [Curriculum Vitae (PDF)](https://lisovyi.me/Lisovyi_Maksym_CV.pdf): Downloadable 1-page CV with verified achievements and employment history.
- [GitHub Profile](https://github.com/lisovyi3441): Source code repositories, architectural experiments, and open-source contributions.
- [Telegram Contact](https://t.me/m_lisovyi): Direct channel for technical inquiries, architecture consultations, and career opportunities.
- [Email Contact](mailto:lisovyi3441@gmail.com): Primary email address for formal correspondence.

## Optional

- [Logistics CRM Source Code](https://github.com/lisovyi3441/logistics-crm): Public GitHub repository for the B2B Freight Logistics platform.
- [Live Logistics CRM Demo](https://crm.lisovyi.me): Live deployment of the freight management system.
- [Live GymControl Demo](https://gym.lisovyi.me): Live deployment of the GymControl CRM and POS engine.