Ruby on Rails Developer

Responsibilities
Design, build, and operate reliable backend services for payment products using Ruby and Ruby on Rails.
Build and maintain APIs, services, and third-party integrations.
Implement payment flows across multiple currencies, countries, and payment methods.
Handle refunds, retries, idempotency, webhooks, asynchronous processing, and partial failures.
Write clean, maintainable, and testable code; participate in code reviews and refactoring.
Improve system performance, reliability, observability, and security.
Investigate production issues, contribute to root-cause analysis, and prevent regressions.
Collaborate with product, QA, and other engineers; communicate risks early.
Requirements
3+ years of backend engineering experience for a mid-level role, or 5+ years for senior level, including hands-on experience building applications with Ruby and Ruby on Rails.
English communication proficiency at B2 level or above.
Experience designing, building, and operating production APIs and backend services, including authentication and authorization, pagination, validation, and consistent error handling.
Practical experience troubleshooting production issues using application logs, metrics, stack traces, and database queries.
Working knowledge of relational databases, preferably PostgreSQL or MySQL, including schema design fundamentals, indexes, transactions, and writing SQL for investigation and troubleshooting.
Experience working with background jobs and asynchronous workflows, including queues, retries, failure handling, and idempotency.
Experience debugging issues across APIs, background jobs, databases, and external service integrations.
Benefits
Working location: Tan My Ward, (District 7), HCMC
Salary range: Up to VND 65,000,000 gross