Senior Fullstack Engineer

X-FLOW is a mobile game development company established in 2018. We gained recognition after the release of Happy Color, the most popular digital coloring book and one of the most successful ad-driven mobile apps in the world.
Key Responsibilities:
Design and develop RESTful APIs using PHP/Laravel.
Build frontend applications using TypeScript/React with a focus on performance and Developer Experience (DX).
Integrate with external services; define and maintain API contracts.
Optimize performance, perform profiling, and reduce latency.
Design database schemas, handle migrations, indexing, and query optimization.
Contribute to quality assurance: write tests (unit/integration/e2e), conduct code reviews, and automate checks.
Ensure observability and reliability: implement logs, metrics, alerts, and traces.
Participate in designing architectural solutions.
Requirements:
4+ years of experience with PHP, strong knowledge of Laravel (DI, queues, profiling, REST, modularity).
4+ years of experience with TypeScript, strong knowledge of React/Redux Toolkit, routing, build processes, and bundle optimization.
Databases: PostgreSQL/MySQL, Redis; experience with schema design, indexes, and transactions.
Message Queues/Buses: Kafka — experience with event-driven integrations.
Security: OAuth2, JWT.
Understanding of DDD, SOLID, 12-Factor App methodology, and observability (Prometheus/Grafana, OpenTelemetry).