Senior Fullstack Engineer (Go/TypeScript)

X-FLOWis a mobile game development company established in 2018. We gained recognition after the release ofHappy Color, the most popular digital coloring book and one of the most successful ad-driven mobile apps in the world. We take pride in our diverse and talented team and partners, spread across the UK, Cyprus, the Netherlands, and other regions worldwide.

Design and develop microservices in Go (REST/gRPC), public and internal APIs.

Develop frontend using TypeScript (React) with a focus on performance and Developer Experience (DX).

Integrate with external services, develop contracts.

Optimize performance, profiling, reduce latency, and scale systems.

Design database schemas, perform migrations, indexing, and query optimization.

Implement and maintain CI/CD, cloud infrastructure (AWS) with Docker/Kubernetes.

Ensure quality: writing tests (unit/integration/e2e), code reviews, automation of checks.

Ensure observability and reliability: logging, metrics, alerting, tracing.

3+ years of commercial development experience, including 3+ years with Golang and 3+ years with TypeScript.

Proficient in Go: context handling, concurrency (goroutines/channels), profiling (pprof), gRPC/REST, generics, modularity.

Strong frontend skills with TypeScript: React, state management (Redux Toolkit), routing, bundle formation, and optimization.

Databases: PostgreSQL/MySQL, Redis; design, indexing, transactions.

Queues/Buses: Kafka/NATS — experience in deg event-driven integrations.

CI/CD: GitLab CI, feature flags, migrations, blue‑green/rolling deployments.

Testing: Jest, Playwright; for Go — testing/testify, integration/e2e.

Understanding of DDD principles, SOLID, 12-factor methodology, observability (Prometheus/Grafana, OpenTelemetry).

Data architecture: CQRS/Event Sourcing, idempotency, deduplication.

Feature flags, experiments/A-B testing, product metrics.

Frontend: TypeScript, React, Redux Toolkit, Playwright.