Sr. Backend Engineer

We are looking for a Senior Backend Engineer with strong experience designing, building, and evolving scalable, reliable, and secure backend systems. This is a hands-on engineering role for someone who goes beyond feature implementation. We are looking for an engineer with strong technical judgment who can understand complex systems end-to-end, contribute to architectural decisions, identify and address technical debt, and continuously improve the quality and maintainability of our platform.

AI is becoming a core part of how we build software. We expect engineers to effectively use modern AI-assisted development tools while maintaining strong ownership and engineering judgment over the code and systems they deliver.

Responsibilities

• Design, build, and evolve scalable backend services and APIs, primarily using Node.js, TypeScript, and Express.js.
• Own technical solutions end-to-end, from design and implementation through deployment, observability, and production support.




• Contribute to the evolution of our backend architecture and participate actively in architectural and technical design decisions.
• Identify, prioritize, and address technical debt, balancing long-term maintainability with product delivery.
• Apply solid software design principles and patterns, choosing appropriate solutions based on context and trade-offs rather than applying patterns by default.
• Design clear application boundaries and separation of concerns across services, business logic, and persistence layers.
• Design and optimize PostgreSQL schemas, queries, indexes, migrations, and transactional workflows.
• Build reliable financial workflows with appropriate strategies for idempotency, concurrency, consistency, retries, failure handling, and reconciliation.
• Design and maintain REST APIs and integrations with internal systems and external providers.
• Design asynchronous and event-driven workflows when appropriate.
• Build systems with strong principles aroun

📌 Senior Backend Engineer (Buenos Aires)
🏢 Kiwi
📍 Buenos Aires