Senior Backend Developer (.NET)

Job offer

Key Responsibilities:

• You will own the design, development, and maintenance of business-critical software projects, including our reservation engine and integration APIs (SOAP/REST).
• You will design the architecture of new projects and lead technical decisions on scalability, performance, and reliability for systems serving for high traffic.
• You will participate in development of business needs and improvement of continuity and quality standards, set coding standards, and mentor junior/mid-level developers through code reviews and pair programming.
• You will solve complex performance and concurrency problems specific to high-load travel/booking systems.

Qualifications

Must have:

• 5+ years of professional experience with C# and the .NET ecosystem, including at least 2 years working on high-traffic production systems.
• Strong knowledge of .NET Framework / .NET 6+.
• Deep understanding of OOP, SOLID principles, Design Patterns, and clean architecture (e.g., layered, hexagonal, or DDD approaches).
• Proven experience with TDD and unit/integration testing (xUnit, NUnit, MSTest, Moq).
• Strong knowledge of SOAP and REST API design and consumption (XML, JSON), including versioning and integration with third-party systems.
• Solid experience with relational databases (MSSQL 2014+, MySQL): query optimization, indexing, and transactions under high load.
• Hands-on experience with caching strategies and distributed caching (Redis).
• Experience building or maintaining high-traffic, high-availability systems: performance profiling, asynchronous programming, concurrency handling.
• Working experience with Git and code review workflows.

Nice to Have:

• Experience with ElasticSearch (search-heavy product catalogs are core to our platform).
• Knowledge of GraphQL.
• Experience with microservices architecture and message brokers (RabbitMQ, Kafka).
• Knowledge of CI/CD tools (Jenkins, GitLab/Bitbucket Pipelines, GitHub Actions).
• Knowledge/Experience with Docker and Kubernetes.
• Experience with ELK Stack (Elasticsearch, Logstash, Kibana) and monitoring tools (Grafana, Prometheus).
• Knowledge of NoSQL databases (e.g., MongoDB, Redis as a data store).
• Experience in travel, e-commerce, or booking domains.
• Passion for clean code and willingness to propose improvements — we are open to ideas, even tech stack changes.

Benefits:

• Work in a modern and stable company
• Competitive salary and benefits package
• Opportunity to work with a dynamic and growing team
• Chance to work on innovative and exciting projects
• Opportunities for professional development and training
• Ability to work in a modern and friendly work environment
• Meal allowance of CZK 123/day
• Language courses at the workplace
• MultiSport card for only CZK 500
• Cafeteria Benefit Plus
• Discounts on company products