Principal Backend Engineer (C#/.NET/Azure) - Hybrid Lisbon

Principal Backend Engineer (C#/.NET/Azure) - Hybrid Lisbon ABOUT THE OPPORTUNITY Join a Portuguese Logistics as a Service platform that handles everything that happens after the customer clicks "buy". It brings orders from every sales channel into a single dashboard, digitizes in-store picking, and optimizes delivery routes in real time, so physical stores work as mini distribution hubs. This is a hands-on Principal Backend Engineer role. You will shape the architecture of the systems that power this operation and also write the code that brings it to life. You'll work in a hybrid model from Lisbon with a flexible schedule, in a dynamic startup culture that values innovation and ownership. PROJECT & CONTEXT The platform is built on microservices, asynchronous communication and an event-driven architecture running on Azure. It processes omnichannel orders, in-store fulfilment workflows and real-time delivery routing for retailers and e-commerce businesses. Your work will include: Owning and influencing the architecture of critical backend systems across multiple domains, including order management, fulfilment and delivery Designing scalable, resilient solutions with C#, .NET and microservices Designing and evolving event-driven and asynchronous workflows that keep orders, stock and deliveries in sync in real time Defining service boundaries, integration approaches and communication patterns Making pragmatic architectural decisions that balance scalability, reliability, maintainability and operational complexity Establishing engineering standards, patterns and best practices across teams Mentoring engineers through design reviews and code reviews Driving improvements in performance, observability, testing, CI/CD and production reliability Identifying technical risks and opportunities early, before they become problems WHAT WE'RE LOOKING FOR (Required) 8+ years of professional software development experience, with significant backend work in C# and modern .NET Strong hands-on experience designing and operating microservices and distributed systems in production Proven experience with event-driven architectures and messaging technologies such as RabbitMQ, Kafka, Azure Service Bus, AWS SQS or equivalent Deep understanding of asynchronous systems and their failure scenarios, including idempotency, retries, dead-letter queues, eventual consistency and transactional messaging Strong experience with relational databases and SQL Server Solid grasp of software architecture and design principles, including DDD, SOLID and Clean Architecture Experience with cloud platforms Experience with automated testing, CI/CD and production observability Track record of mentoring engineers and influencing technical decisions across teams Experience using AI development assistants as part of your engineering workflow Good communication skills in English (required) Based in Lisbon or able to commute to the Lisbon…