Senior Backend Developer .NET

我们的酒店管理解决方案由多个面向领域的微服务（domain-oriented microservices）组成，并由数个跨职能团队共同开发。您将参与开发面向酒店行业的分布式系统的一部分。该系统由多个面向领域的微服务组成，由若干跨职能团队共同开发。通过您的工作，您将为全球数以千计酒店员工的工作体验带来改善。 

随着业务的发展，需招募高级Backend开发工程师若干名，详情如下： 

主要职责范围 

1. 系统功能的开发、实施与维护 

• 运用领域驱动设计（Domain-Driven Design）的原则，在现有的微服务（microservice）生态系统中设计可扩展的解决方案。 
• 实现复杂的酒店管理业务逻辑，包括预订、费用结算和报表功能。 
• 在系统架构不断进化的过程中，确保其兼容性。 
• 设计容错组件，以应对高吞吐量的数据处理任务。 
• 与产品团队协作，将业务需求进行技术转化。 

2. 为第三方构建专用的数据导出解决方案 

• 为与酒店管理系统对接的第三方系统设计并实现稳健的 API 集成。 
• 为酒店管理系统（PMS）、渠道管理系统（Channel Management）及收益管理工具创建数据导出机制。 
• 为B2B集成实施安全的身份验证和授权机制。 
• 开发支持多种格式（XML, JSON, CSV）的基于文件的导出解决方案。 
• 确保外部数据交换的一致性和可靠性。 
• 管理API版本控制，并维护现有集成兼容性。 

3. 为分析和报表目的构建可扩展的数据聚合策略 

• 设计高效的数据聚合管道，用于酒店经营分析和商业智能（BI）。 
• 对于酒店大数据场景设计实时和批处理解决方案。 
• 创建针对入住率、收入和运营指标报表的优化数据模型。 
• 开发处理复杂酒店数据转换的ETL（抽取、转换、加载）流程。 
• 确保来自多个数据源的数据质量和一致性。 
• 与数据分析师协作，理解报表需求并优化查询性能。 

4. 每日进行代码审查并参与评审流程 

• 专注于代码质量、安全性和性能进行彻底的代码审查。 
• 确保代码符合编码标准、SOLID原则及既定的架构模式。 
• 就实现方法提供富有建设性的反馈并提出改进建议。 
• 审查数据库查询，寻找优化机会并发现潜在的性能问题。 
• 验证错误处理、日志记录和监控功能的正确实施。 
• 提交带有清晰描述和上下文的、文档齐全的拉取/合并请求（Pull/Merge Requests）。 
• 及时响应审查反馈并落实改进建议。 
• 参与关于实现方法和设计决策的技术讨论。 
• 遵循既定的分支策略和合并流程。 
• 确保所有代码变更都包含适当的单元测试和集成测试。 
• 保持较高的代码覆盖率和质量。 

5. 使用高级工具优化API和报表中SQL查询的性能 

• 分析并优化处理大型酒店数据集的复杂PostgreSQL查询。 
• 为时序酒店数据设计高效的数据库索引和分区策略。 
• 实施查询优化技术，包括适当的连接（Join）策略和子查询优化。 
• 使用数据库性能分析工具识别并解决性能瓶颈。 
• 监控查询执行计划，并在适当情况下实施缓存策略。 
• 优化Entity Framework查询并实施高效的数据访问模式。 

6. 在敏捷开发的框架下进行协作式、迭代式的软件开发 

• 积极参与例会、迭代规划和评审会议等。 
• 与质量保证（QA）、产品构架以及产品团队等跨职能团队进行有效协作。 
• 通过提供准确的工作量预估和技术洞察，参与迭代规划。 
• 在保持代码质量和交付时间线的前提下，适应不断变化的需求。 
• 通过自动化测试和监控实践持续集成与持续部署（CI/CD）。 
• 参与生产环境问题的事件响应和事后分析（Post-mortem analysis）。 

技术需求 

• C# 9, .NET Core：使用最新的C#特性和现代.NET生态系统。 
• PostgreSQL：高级SQL特性、JSON支持、分区及性能调优。 
• 微服务：面向服务的架构、服务间通信及分布式系统模式。 
• Swagger：API文档生成、测试及客户端代码生成。 
• Docker：容器化、编排及部署策略。 
• Redis：缓存、会话管理及分布式数据结构。 
• Kafka：事件流处理、消息队列及服务间的异步通信。 
• Elastic Search（加分项）：全文搜索、日志聚合及分析。 
• Visual Studio 2022 / Resharper / Rider：配备高级调试和重构工具的专业开发环境。 

Your job will be to develop a part of a distributed system that serves the hospitality industry. The system consists of many domain-oriented microservices developed under a few cross-functional teams. You can bring a smile to the faces of thousands of people working in hotels across the globe.

Key Areas of Responsibilities

Designing, implementing, and maintaining new functionalities within a living system

• Design scalable solutions within existing microservices ecosystem using Domain-Driven Design principles
• Implement complex business logic for hotel management operations including reservations, billing, and reporting
• Ensure backward compatibility while evolving system architecture
• Design fault-tolerant components that handle high-volume hospitality data processing
• Collaborate with product teams to translate business requirements into technical specifications

Building dedicated export solutions for 3rd parties

• Design and implement robust APIs integration for external hotel management systems
• Create data export mechanisms for property management systems, channel managers, and revenue management tools
• Implement secure authentication and authorization for B2B integrations
• Develop file-based export solutions supporting various formats (XML, JSON, CSV)
• Ensure data consistency and reliability in external data exchanges
• Manage API versioning and maintain backward compatibility for existing integrations

Building scalable aggregated data strategy for analytical and reporting purposes

• Design efficient data aggregation pipelines for hotel performance analytics and business intelligence
• Implement real-time and batch processing solutions for large-scale hospitality data
• Create optimized data models for reporting on occupancy, revenue, and operational metrics
• Develop ETL processes that handle complex hotel data transformations
• Ensure data quality and consistency across multiple data sources
• Collaborate with data analysts to understand reporting requirements and optimize query performance

Performing code reviews daily and participating in code review process

• Conduct thorough code reviews focusing on code quality, security, and performance
• Ensure adherence to coding standards, SOLID principles, and established architectural patterns
• Provide constructive feedback on implementation approaches and suggest improvements
• Review database queries for optimization opportunities and potential performance issues
• Validate proper error handling, logging, and monitoring implementation
• Submit well-documented pull/merge requests with clear descriptions and context
• Respond promptly to review feedback and implement suggested improvements
• Engage in technical discussions about implementation approaches and design decisions
• Follow established branching strategies and merge procedures
• Ensure all code changes include appropriate unit and integration tests
• Maintain high code coverage and quality metrics

Using advanced tools to optimize performance of SQL queries used in APIs and reports

• Analyze and optimize complex PostgreSQL queries handling large hospitality datasets
• Design efficient database indexes and partitioning strategies for time-series hotel data
• Implement query optimization techniques including proper join strategies and subquery optimization
• Use database profiling tools to identify and resolve performance bottlenecks
• Monitor query execution plans and implement caching strategies where appropriate
• Optimize Entity Framework queries and implement efficient data access patterns

Working in a collaborative and iterative software development process with an Agile team

• Actively participate in Scrum ceremonies including daily standups, sprint planning, and retrospectives
• Collaborate effectively with cross-functional teams including QA, Infrastructure, and Product Team people
• Contribute to sprint planning by providing accurate effort estimates and technical insights
• Adapt to changing requirements while maintaining code quality and delivery timelines
• Practice continuous integration and deployment with automated testing and monitoring
• Participate in incident response and post-mortem analysis for production issues

Technologies used:

• C# 9, .NET Core - Latest C# features and modern .NET ecosystem
• PostgreSQL - Advanced SQL features, JSON support, partitioning, and performance tuning
• Microservices - Service-oriented architecture, inter-service communication, and distributed system patterns
• Swagger - API documentation, testing, and client code generation
• Docker - Containerization, orchestration, and deployment strategies
• Redis - Caching, session management, and distributed data structures
• Kafka - Event streaming, message queuing, and asynchronous communication between services
• Elastic Search (nice to have) - Full-text search, log aggregation, and analytics
• Visual Studio 2022 / Resharper / Rider - Professional development environment with advanced debugging and refactoring tools

任职要求 

• 英语能力：要求具备流利的英语口语和书面沟通能力，能够向技术和非技术利益相关者传达复杂的技术概念；具备撰写清晰的技术文档和API规范的经验；能有效地在国际化的分布式团队中协作。 
• 编程范式：精通面向对象（OOP）和函数式编程（FP）范式，对OOP原则有深刻理解，具备C#函数式编程概念的经验，并掌握设计模式。 
• .NET技术：具备.NET 8/9和Entity Framework的扎实经验，精通最新.NET特性；高级Entity Framework Core知识（包括迁移、查询优化和性能调优）；具备依赖注入、中间件和ASP.NET Core管道的经验。 
• PostgreSQL：具备丰富的PostgreSQL实战经验，拥有高级SQL技能（包括复杂连接、窗口函数和CTE）；掌握数据库设计和规范化原则；具备PostgreSQL特定功能（如JSON/JSONB、数组和自定义数据类型）的经验；拥有数据库性能调优和查询优化的知识。 
• 数据库性能：具备编写代码及配套测试的能力，熟悉测试驱动开发（TDD）和行为驱动开发（BDD）实践；掌握单元测试、集成测试和端到端测试策略；了解代码覆盖率分析和质量指标；遵循整洁代码原则和SOLID设计模式。 
• 软性素质：思维开放、积极主动，乐于学习新技术并适应变化的需求；能主动发现问题并在其影响团队前解决；乐于协作解决问题并分享知识；具备自我激励的职业发展态度，定期参与技术社区并紧跟行业趋势；能主动提出并实施流程改进方案。 
• 工作经验：至少3年同类职位经验，且在IT行业拥有至少5年经验；在高级后端开发岗位上有可证实的业绩；具备领导技术项目并指导其他开发人员的经验；具备处理复杂分布式系统的能力。 

加分技能（Nice To Have） 

• Linux与Docker基础：熟练使用Linux命令行及系统管理基础；具备Docker容器化、Docker Compose及容器编排的经验。 
• 领域驱动设计（DDD）：了解DDD概念，包括限界上下文（Bounded Contexts）、聚合（Aggregates）和领域事件（Domain Events）。 
• CQRS与事件溯源模式：具备命令查询职责分离（CQRS）和事件溯源（Event Sourcing）架构及事件存储管理的经验。 
• 分布式系统与Web服务：具备微服务通信模式（同步和异步）的经验；了解分布式事务管理和最终一致性。 
• AWS技术：具备AWS RDS PostgreSQL及其他AWS数据库相关技术的经验者优先，包括AWS RDS配置、监控与优化；AWS数据库迁移服务及备份策略；AWS CloudWatch监控及性能洞察。 
• 酒店系统经验：具备酒店系统经验并对酒店应用熟悉者将被视为极大的优势，包括了解酒店运营（预订、入住/退房、计费流程）；熟悉酒店行业标准及集成（PMS, CRS, GDS）；了解酒店收益管理和报表要求；熟悉酒店特定的数据模型和业务规则。 

Strong verbal and written communication skills in English are required

• Ability to communicate complex technical concepts to both technical and non-technical stakeholders
• Experience with writing clear technical documentation and API specifications
• Effective collaboration in international, distributed teams

Fluent in Object-Oriented and Functional Programming paradigms

• Deep understanding of OOP principles
• Experience with functional programming concepts in C#
• Knowledge of design patterns

Knowledge of .NET 8/9 and Entity Framework

• Proficiency in latest .NET features
• Advanced Entity Framework Core knowledge including migrations, query optimization, and performance tuning
• Experience with dependency injection, middleware, and ASP.NET Core pipeline

Strong experience with PostgreSQL

• Advanced SQL skills including complex joins, window functions, and CTEs
• Database design and normalization principles
• Experience with PostgreSQL-specific features like JSON/JSONB, arrays, and custom data types
• Knowledge of database performance tuning and query optimization

Good understanding of and hands-on experience with database performance aspects

• Index design and optimization strategies
• Query execution plan analysis and optimization
• Database monitoring and performance metrics analysis
• Experience with connection pooling and transaction management

Capability of writing clean code along with tests

• Test-driven development (TDD) and behavior-driven development (BDD) practices
• Unit testing, integration testing, and end-to-end testing strategies
• Code coverage analysis and quality metrics
• Clean code principles and SOLID design patterns

Open-minded, proactive person

• Willingness to learn new technologies and adapt to changing requirements
• Initiative in identifying and solving problems before they impact the team
• Collaborative approach to problem-solving and knowledge sharing

Proactive attitude and continuous improvement

• Self-motivated approach to professional development
• Regular participation in technical communities and staying updated with industry trends
• Initiative in proposing and implementing process improvements

Minimum 3 years of experience with similar position and minimum 5 years of experience with IT industry

• Proven track record in senior backend development roles
• Experience with leading technical initiatives and mentoring other developers
• Demonstrated ability to work with complex distributed systems

Nice To Have Skills

Basics of Linux and Docker

• Linux command line proficiency and system administration basics
• Docker containerization, Docker Compose, and container orchestration

Domain-Driven Design

• DDD concepts including bounded contexts, aggregates, and domain events

Experience with CQRS and Event Sourcing patterns

• Command Query Responsibility Segregation (CQRS) implementation
• Event Sourcing architecture and event store management
• Experience with event-driven architecture patterns

Experience with distributed systems and web services

• Microservices communication patterns (synchronous and asynchronous)
• Distributed transaction management and eventual consistency

Experience with AWS RDS PostgreSQL and other AWS database-related technologies is a plus

• AWS RDS configuration, monitoring, and optimization
• AWS database migration services and backup strategies
• AWS CloudWatch monitoring and Performance Insights

Experience with hospitality systems and familiarity with hospitality applications is a strong plus

• Understanding of hotel operations, including reservations, check-in/check-out, and billing processes
• Knowledge of hospitality industry standards and integrations (PMS, CRS, GDS)
• Experience with hotel revenue management and reporting requirements
• Familiarity with hospitality-specific data models and business rules