Senior Software Engineer (Python + Rust)

The type of contract is a full-time legal agreement in Bulgaria, Serbia, and Turkey or a B2B contract.

Duties and Responsibilities:

• Design and implement backend services in Rust within a microservices architecture.
• Maintain and evolve existing Python services (FastAPI) where it's the right tool for the job.
• Write maintainable, testable, and performant code; participate in code reviews and raise the engineering bar across the team.
• Work with QA and DevOps to improve reliability, observability, and performance of our services.
• Contribute to architectural decisions: choosing the right language for each problem, inter-service communication patterns, and data modeling.

Qualifications and Experience:

• 5+ years of professional backend development experience.
• Solid production experience with Rust (minimum of 3 years).
• Strong Python: FastAPI or similar modern frameworks, asynchronous programming (asyncio), and type-driven development (mypy, pydantic).
• Deep understanding of microservices and communication patterns: sync/async, event-driven, message brokers (Kafka / RabbitMQ / NATS), gRPC/REST.
• Working-level PostgreSQL: indexes, transactions, isolation levels, locking, query plans.
• SOLID, dependency injection, and clean architecture — applied in practice, not just in theory.
• Working knowledge of k8s, containers, networking, and CI/CD.
• English B2 or higher.

Nice to Have but not Obligatory: 

• Experience migrating Python services to Rust under real load (with measurements and clear motivation).
• Exposure to vector databases (e.g., Qdrant).
• Experience integrating with LLM APIs (OpenAI, Anthropic).
• Familiarity with LangChain / LangGraph and RAG