Principal Software Engineer (Ruby on Rails)

A leading B2B SaaS company operating at global scale, building and maintaining a cloud-native platform with a diverse, cross-functional engineering organisation. The engineering team works across a Ruby on Rails core backend, Go-based services, and AWS infrastructure, with a strong emphasis on operational excellence, security, and AI-assisted delivery practices.

As a Principal Product Engineer, you will drive outcomes across the team and technical system by leading design, implementation, rollout, and operational excellence. You will work primarily in a Ruby on Rails codebase to deliver product features end-to-end, with occasional contributions to Go-based services. This role requires a strong security mindset, including clear understanding of data privacy, credential protection, and the responsible use of corporate systems.

Technical Leadership

• Design, develop, and operate backend features in Ruby on Rails with strong software engineering fundamentals and pragmatic delivery
• Design and evolve RESTful APIs and service boundaries with clear tradeoffs and maintainable interfaces
• Model data effectively and optimize SQL performance; identify and address bottlenecks and system inefficiencies
• Architect and operate cloud-native applications on AWS (and related tooling) with pragmatic use of Docker/Kubernetes where appropriate
• Improve observability (logs/metrics/traces), incident response, and post-incident learning to raise system reliability

Delivery Ownership & Cross-Functional Collaboration

• Own delivery end-to-end from problem definition through production rollout, ensuring quality and operational readiness
• Partner with Product, Design, QA, and DevOps to clarify requirements, reduce ambiguity, and deliver outcomes aligned to business goals
• Plan and execute production releases, coordinate stakeholders, and continuously improve deployment safety and speed via CI/CD

Engineering Excellence & Quality

• Set and model best practices for clean, maintainable code; lead a strong code review culture
• Increase confidence and reduce manual testing via effective automated tests and robust review processes
• Operate and improve CI/CD pipelines to support frequent and safe delivery
• Ensure AI-assisted speed never compromises security, privacy, scalability, or compliance requirements

AI-Assisted Delivery Practices

• Use AI to accelerate prototyping and iteration (requirements exploration, code scaffolding, test generation, refactoring)
• Quickly identify flaws in AI-generated output and correct them; maintain strong human verification habits (testing, reviews, threat modeling)
• Improve the clarity of logs, runbooks, and technical documentation so both humans and AI tools can understand and operate the system effectively

Scope & Collaboration

• Primary focus is Rails-first backend/API delivery, with pragmatic cross-functional reach (infra/observability/quality) as needed to unblock outcomes
• Collaborate across time zones with global stakeholders and engineering partners
• Report to the Engineering Director

Minimum Requirements

• 8+ years in software development, with 3+ years of recent hands-on experience in Ruby on Rails
• Experience designing and operating web services and microservices in distributed 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 skills with the ability to work effectively with cross-functional teams
• Professional English proficiency for global collaboration

Nice to Have

• Kubernetes/EKS experience in production environments
• Monitoring and logging experience (e.g., Datadog, Prometheus, Grafana, ELK)
• Experience with message brokers and event-driven architectures (e.g., Kafka, RabbitMQ)
• Experience integrating LLM APIs into products or internal tools (prompting, async workflows, handling non-deterministic outputs)

Work Arrangement & Wellbeing

• Hybrid working: 2 days in-office, 3 days work from home per week
• Flexible start time between 8AM–9AM, Monday to Friday
• Full salary paid during probation period
• Social Insurance, Health Insurance, and Unemployment Insurance applied from probation (calculated on 100% salary)
• Private health insurance and accident insurance from day one; extended to family members from managerial level
• Annual health check
• Well-equipped hardware: MacBook Pro and additional monitor provided
• Billiards and running club
• Annual company trip and quarterly team-building activities

Leave & Bonuses

• 13th month salary bonus
• 16–24 paid days off per year (and more)
• Extra 5 days paternity leave

Career & Development

• Clear career path and progression framework
• Sponsorship for foreign language learning and international technology certifications
• External and internal training courses, soft-skill workshops, and tech seminars
• Monthly and bi-annual recognition awards
• Performance and salary review twice per year (June and December)