Ruby on Rails Developer

Working location: Tan My Ward, (District 7), HCMC

Salary range: Up to VND 80,000,000 gross

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 middle level, 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.

*** Nice to have

● Payment or fintech experience.

● Redis, Sidekiq, Kafka (or similar) experience.

● AI-assisted coding/debugging tools (Claude Code/Copilot/Cursor) with strong review discipline.

● Cloud infrastructure and containers.

● PCI-aware development practices.