Principal Full Stack Engineer

Through proprietary software and AI, along with a focus on customer delight, Sleek makes the back-office easy for micro SMEs. We give Entrepreneurs time back to focus on what they love doing - growing their business and being with customers. With a surging number of Entrepreneurs globally, we are innovating in a highly lucrative space. We operate 3 business segments: Corporate Secretary: Automating the company incorporation, secretarial, filing, Nominee Director, mailroom and immigration processes via custom online robots and SleekSign. We are the market leaders in Singapore with ~5% market share of all new business incorporations Accounting & Bookkeeping: Redefining what it means to do Accounting, Bookkeeping, Tax and Payroll thanks to our proprietary SleekBooks ledger, AI tools and exceptional customer service FinTech payments: Overcoming a key challenge for Entrepreneurs by offering digital banking services to new businesses Sleek launched in 2017 and now has around 17,500 customers across our offices in Singapore, Hong Kong, Australia and the UK. We have around 600 staff with an intact startup mindset. We have recently raised Series B financing off the back of >70% compound annual growth in Revenue over the last 5 years. Sleek has been recognised by The Financial Times, The Straits Times, Forbes and LinkedIn as one of the fastest growing companies in Asia. Backed by world-class investors, we are on track to be one of the few cash flow positive, tech-enabled unicorns based out of Asia Pacific. At Sleek, we are on a mission to streamline operations and elevate customer experience through intelligent automation and modern engineering.

About the Role

As a Principal Full Stack Engineer, you will be one of Sleek's most senior individual contributors, leading the architectural vision and end-to-end delivery of complex web applications and core platform services. You'll operate with a high degree of autonomy, solving ambiguous engineering problems while helping raise the technical standards of the wider engineering organisation.

Mission: In this role you will balance deep technical execution across the full stack-from intuitive user interfaces to scalable distributed backend systems-while championing developer productivity and embedding agentic AI workflows into our products.

Key Outcomes

1. Full Stack Architecture & Product Delivery Architect, build, and maintain production-grade SaaS applications across the entire stack using modern JavaScript/TypeScript, frontend frameworks (React/Vue), and backend environments (Node.js/NestJS). Design resilient APIs, database schemas (Postgres, MongoDB), and cloud-native services capable of scaling with business growth. Partner closely with Product, Design, and Engineering leaders to turn complex operational and financial challenges into simple, robust software solutions.
2. Agentic AI Integration Architect and implement agentic AI capabilities and intelligent workflows into production applications (e.g., document processing, automated classification, and decision-support systems). Establish reliability patterns for AI features, including guardrails, evaluation frameworks, fallback strategies, and observability for model behavior.
3. Harness Engineering & Engineering Productivity Build and maintain engineering harnesses, automated workflows, and internal developer tooling that eliminate friction in the engineering lifecycle. Introduce modern AI-assisted development tools (such as Cursor, automated test/documentation generators, and debugging aids) to significantly increase productivity across the entire engineering organization.
4. Platform Performance & Technical Leadership Identify and eliminate performance bottlenecks in APIs, data pipelines, and backend microservices. Mentor senior and mid-level engineers, lead technical architecture reviews, and raise the bar for code quality, testing, and system design across Sleek.

Must-Have Requirements

• Depth- 8+ years shipping and running production SaaS.
• Architecture- scalable distributed systems, APIs, and service boundaries you've had to live with.
• TypeScript / Node.js- years in this ecosystem, not a recent port from another language.
• Relational and document databases both.
• Full-stack ownership- you take a feature from schema to API to UI and out to production without handing off the parts you like least. You're strongest somewhere, but you're not helpless anywhere.
• Developer platform- you've built internal developer tooling, automation, and paved paths that other engineers depend on daily, and treated them as products with users rather than side projects.
• Cloud and operations- you deploy it, monitor it, respond to incidents, and continuously improve it in production. Observability and security are part of the job, not someone else's.
• Production AI - You've built and shipped AI-powered product capabilities (agents, intelligent automation, document processing, workflow orchestration, or similar) and understand how to evaluate,