Senior PHP Backend Developer

About the Role We are looking for an experienced Backend Engineer to join our development team and contribute primarily to the development and maintenance of our REST API. Our backend is built on a custom PHP framework rather than Laravel or Symfony. The system follows a modular monolith architecture and PSR standards, runs in Docker, and is hosted on Open Telekom Cloud. We are looking for an engineer who enjoys working with clean architecture, well-structured code, and modern software development practices, and who is comfortable understanding and working with the underlying components that traditional frameworks usually abstract away. AI-assisted development is also part of our daily engineering workflow, so we are looking for someone who knows how to use AI coding tools effectively while maintaining full ownership of code quality. Responsibilities Develop, maintain, and improve backend services and REST APIs using PHP 8.4+.Work within and contribute to our custom PHP framework, including components such as routing, dependency injection, and middleware.Design clean, maintainable, and modular backend solutions following SOLID principles, design patterns, and PSR standards.Contribute to a modular monolith architecture, maintaining clear separation between application modules and business domains.Design and optimize MySQL database schemas, queries, indexes, and transactions.Work with Redis for use cases such as caching, sessions, queues, and rate limiting.Design REST APIs following established practices for resource naming, HTTP methods, status codes, pagination, filtering, and versioning.Implement and maintain secure API authentication and authorization mechanisms.Work with Docker for local development and containerized environments.Collaborate within existing CI/CD processes and troubleshoot applications in Linux-based environments.Use AI coding assistants as part of the daily development workflow while reviewing, validating, and taking responsibility for generated code.Contribute to future AI-powered product features and integrations where applicable. Requirements PHP & Software Engineering Strong professional experience with PHP, including modern PHP 8.4+ features such as typed properties, enums, readonly properties, match expressions, and attributes.Strong understanding of Object-Oriented Programming (OOP), SOLID principles, and common design patterns.Comfortable developing without relying on large frameworks such as Laravel or Symfony.Good understanding of how framework components work internally, including:RoutingDependency Injection containersMiddlewareGood knowledge of PSR standards.Architecture Experience working with modular monolith architecture and structuring independent modules within a single codebase.Understanding of Domain-Driven Design (DDD) fundamentals, including bounded contexts and separation of concerns.Strong appreciation for clean, maintainable, and scalable software architecture.Databases Strong experience with MySQL, including:Schema designIndexingQuery optimizationTransactionsExperience with Redis for caching, sessions, queues, rate limiting, or similar use cases.REST API Development Strong experience designing and developing REST APIs.Good understanding of REST best practices, including:HTTP methods and status codesResource namingPagination and filteringAPI versioningUnderstanding of API authentication and authorization mechanisms such as OAuth2, JWT, and API keys.DevOps & Infrastructure Solid hands-on experience with Docker, including writing Dockerfiles, using Docker Compose, and debugging containers.Basic understanding of CI/CD pipelines.Comfortable working with the Linux command line.AI-Assisted Development Practical experience using modern AI coding assistants, such as Claude Code, Codex, or similar tools, as part of daily software development.Able to use AI to accelerate development while independently reviewing, understanding, and validating generated code.Maintains full ownership and responsibility for software quality rather than relying blindly on AI-generated solutions.Interest in integrating AI/LLM capabilities into products, such as working with LLM APIs or developing AI-powered features, is a strong advantage. Nice to Have Experience building or maintaining custom PHP frameworks.Strong knowledge of clean architecture and Domain-Driven Design.Experience with Open Telekom Cloud or similar cloud environments.Experience integrating LLM APIs or developing AI-powered application features.Experience working in modern, AI-assisted engineering environments. What We’re Looking For We are looking for an engineer who is comfortable going beyond framework conventions and understands how backend systems work under the hood. You should be able to work independently, reason about architecture and code quality, and contribute to a mature codebase without depending on Laravel or Symfony abstractions. You should also be comfortable adopting modern development approaches, including AI-assisted engineering, while maintaining strong software engineering standards and taking ownership of the quality of your work. What We Offer: Competitive salary and benefits.A dynamic and supportive work environment.Opportunities for professional growth and development.The chance to work on cutting-edge technologies and projects. Who we are: Wolkk is an offshore outsourcing company dedicated to connecting international clients with top talent in Indonesia. Our mission is to enable young professionals in Indonesia to learn and grow by working with international clients. We help clients recruit and manage their employees in Indonesia, fostering an environment where talent can thrive and businesses can achieve their goals. Join us at Wolkk and be part of a dynamic team that bridges global opportunities with local expertise. Our values: Trust and RespectThirst for learningAgile and FlexibleQuality Driven