Senior Backend Developer

Quick Facts

Senior backend role focused on a workflow builder product.

Description

Rozwijamy Workflow Builder, a product for visual creation and execution of processes. We are looking for a senior engineer to extend our backend and workflow engine, implement the product for customers, and integrate it with their systems.

Responsibilities

• Develop the product backend, APIs, and mechanisms for executing workflow graphs.
• Build and develop integrations of the product with external systems.
• Deploy to customers and integrate with their systems.
• Scale workers, optimize performance and reliability of processes.
• Design modules, write tests, production diagnostics, and conduct code reviews.
• Lead tasks from design through deployment and maintenance.
• Align requirements with customer and team.
• Report risks and blockers and propose solutions.
• Share knowledge, participate in code reviews, and use feedback.
• Discuss technical solutions with customers in English.

Requirements

• Very good knowledge of TypeScript and Node.js, and experience developing production backends.
• Production experience with Temporal (or another durable execution engine) and readiness to work with Temporal.
• Understanding of determinism and replay, retries, durable timers, and resumptions.
• Ability to safely change code that is handling ongoing processes.
• Idempotency, deduplication, handling partial failures, and compensations.
• Understanding dependencies between steps and parallel branches of a workflow.
• Designing and implementing scalable systems.
• Horizontal scaling of workers in Temporal (or similar) with concurrency control and removal of bottlenecks.
• PostgreSQL experience at large data volumes: query optimization, indexes, partitioning, transactions, and migrations.
• Experience with Redis (or similar): cache, TTL, invalidation, and data consistency.
• Deploying and maintaining applications in Azure or AWS; knowledge of one and readiness to work in the other.
• REST API, webhooks, and SSE.
• Authentication, authorization, tenant data isolation, and secret management.
• Docker, CI/CD, integration and load tests, monitoring, and diagnosing failures.
• Experience working with AI agents for implementing, testing, or analyzing code.
• Ability to review AI agent changes and continue working in that setup.
• English at C1 level.

Benefits

• Opportunity to build and evolve a workflow execution engine used by customers.
• Independent ownership of tasks from design through deployment and maintenance.