Full Stack AI Engineer (Ruby on Rails as core)

About Perx: Perx Technologies is a behavioral intelligence and marketing SaaS Platform headquartered in Singapore, helping large enterprises and digital natives transform from transient and transactional brands to delivering meaningful B2B2X engagements and relationships in the mobile-first economy. The API-first platform enables businesses to focus on use cases and creative engagements to solve their monetization, retention, and user behavior challenges across disparate CRM and marketing solutions in a matter of minutes.Quick Snapshot:

The Senior Full Stack Software Engineer is a high-impact role responsible for designing and scaling our next-generation distributed platform, including agentic AI systems and autonomous workflow orchestration. You will work closely with architecture and product teams to build resilient, high-performance software that powers intelligent decisioning and real-time engagement.You will help shape the technical direction of the platform, including the integration of AI agents that can reason, act, and coordinate across services, APIs, and data systems.What’s the Role?

You will:

• Influence and contribute to the technical vision of platform architecture, including AI-native and agent-driven system design
• Design and implement scalable, multi-tenant, microservices-based architectures with embedded agentic workflows
• Build and deploy autonomous and semi-autonomous AI agents that support:
  • Customer engagement orchestration
  • Decision automation and personalization
  • Event-driven workflow execution across distributed systems
• Define information architecture and system design, including data models, APIs, and service interactions that support agent reasoning and execution
• Design solution strategies focused on scalability, maintainability, interoperability, and AI extensibility
• Ensure clean, modular, testable code aligned with engineering best practices and agent-safe design principles
• Conduct and enforce rigorous code reviews and architectural governance
• Identify and mitigate technical risks across traditional services and AI/agent workflows
• Implement robust testing strategies (unit, integration, performance, and AI/agent behavior validation)
• Collaborate with product and architecture teams to define agent capabilities and system boundaries
• Mentor engineers on modern software engineering practices and agent-based system design
• Leverage modern AI tooling, open-source frameworks, and emerging technologies to accelerate the development of intelligent systems
• Drive troubleshooting, debugging, and root cause analysis across distributed systems and agent execution layers

Who Are We Looking For?

• BS/MS in Computer Science, Engineering, or equivalent experience
• 5+ years of application development experience in Ruby on Rails or other OO languages
• Strong experience building multi-tenant, microservices-based distributed systems
• Hands-on experience with API and SDK design, scalable backend systems, and service-oriented architectures
• Proven experience in AWS, Docker, and DevOps practices in agile environments
• Experience with automation tools (Ansible or similar) is a plus
• Strong knowledge of relational databases (PostgreSQL), data modeling, and system design
• Frontend expertise in Angular 2+, AngularJS, TypeScript, JavaScript, HTML5, CSS
• Strong understanding of object-oriented design, design patterns, and multi-tier architectures
• Experience building highly interactive and real-time applications

Agentic AI & Modern Engineering (Highly Valued):

• Experience or strong interest in building agentic AI systems, autonomous workflows, or LLM-powered applications
• Familiarity with AI orchestration patterns (tool use, planning loops, memory systems, multi-agent coordination)
• Experience integrating AI models into production-grade systems (LLMs, APIs, vector databases, etc.)
• Ability to design systems where software agents can execute tasks, make decisions, and interact with APIs/services
• Strong systems thinking for balancing determinism, reliability, and AI-driven variability

What’s on Offer?

• Collaborative environment in one of Asia’s leading Martech and Fintech SaaS companies
• Opportunity to work with global enterprise clients across banking, retail, insurance, and telecom industries
• Exposure to platforms serving 1Bn+ end users and 50Mn+ daily consumer engagements
• High-growth environment with cross-functional development opportunities across product, engineering, and AI innovation
• Strong investment in engineering excellence and emerging technology capabilities, including AI-native platform development

Why Join Us?

We believe product innovation comes from people innovation. We are actively evolving into an AI-first, agent-driven platform company, redefining how brands build meaningful customer relationships in a mobile-first world.If you are excited by the idea of building scalable systems where autonomous agents power real-time customer engagement at global scale, this is your opportunity to shape the future with us.