Principal Software Engineer (Ruby on Rails, AI)

Technical Leadership: Design, develop, and operate backend features in a Ruby on Rails and core services, evolve RESTful APIs and service boundaries, model data effectively, optimize SQL performance, and architect and operate cloud-native applications on AWS with pragmatic use of Docker/Kubernetes where appropriate. Improve observability, incident response, and post-incident learning to raise system reliability.

Delivery Ownership & Cross-Functional Collaboration: Own delivery from problem definition through production rollout, collaborate with Product, Design, QA, and DevOps to clarify requirements, reduce ambiguity, and deliver outcomes aligned to business goals. Plan and execute production releases, and continuously improve deployment safety and speed (CI/CD).

Engineering Excellence & Quality: Set and model best practices for clean, maintainable code, increase confidence and reduce manual testing via effective automated tests and robust review processes, operate and improve CI/CD pipelines, and ensure speed does not compromise security, privacy, scalability, or compliance requirements.

AI-Assisted Delivery Practices: Use AI to speed up prototyping and iteration, quickly identify flaws in AI-generated output and correct them, and improve the clarity of logs, runbooks, and technical documentation to be understandable for both humans and AI tools.

Scope & Collaboration: Focus on Rails-first backend/API delivery and collaborate across time zones with global stakeholders and engineering partners as needed.

5+ years of software engineering experience, including significant experience in building and operating production web applications.

Strong proficiency in Ruby on Rails or a strong willingness and demonstrated ability to ramp up quickly and work day-to-day in a Rails codebase.

Experience in designing and operating web services and microservices in production environments.

Strong hands-on experience with AWS and cloud-native development practices.

Deep knowledge of relational databases and practical experience with data modeling and SQL performance tuning.

Demonstrated ability to lead projects end-to-end and coordinate releases across stakeholders.

Strong communication and ability to work effectively with cross-functional teams.

Professional English proficiency for global collaboration.

Kubernetes/EKS experience in production.

Monitoring/logging experience (e.g., Datadog, Prometheus, Grafana, ELK).

Message brokers/event-driven architectures (e.g., Kafka, RabbitMQ).

Experience integrating LLM APIs into products or internal tools (prompting, async workflows, handling non-deterministic outputs).

Languages: Ruby on Rails (core), Go (selected services)

Datastores: MySQL, DynamoDB, Redis

Infrastructure: AWS (EKS, ECR, RDS, S3, SQS/SNS), Kubernetes, Docker, Terraform

Communication: Slack, Notion, Zoom

Monitoring: Datadog, Rollbar

Source control: GitHub

CI/CD: Argo CD, CircleCI, GitHub Actions

Ticketing: Jira

Security: Dependabot, SonarQube

Employees have the flexibility to work two days in the office and three days from home

Work hours are flexible, with the option to start between 8AM-9AM from Monday to Friday

Full salary during the probation period

Eligibility for various insurance benefits, including social, health, and unemployment insurance, as well as private health and accident insurance

Additional perks such as a 13th-month salary, 16-24 paid days off, and paternity leave

Opportunities for annual company trips, quarterly team building activities, and participation in billiards and running clubs

Access to an annual health check and well-equipped facilities, including a MacBook Pro and additional monitor

Clearly defined career paths for employees

Sponsorship for foreign language and international technology-related certifications

Access to both internal and external training courses, soft-skill workshops, and tech seminars

Recognition awards and biannual performance and salary reviews (in June and December)

PEGASI – IT Recruitment Consultancy | Email: recruit@pegasi.com.vn | Tel: +84 28 3622 8666