Senior Fullstack Developer (Next.js & NestJS)

Job description

We are building a high-performance B2B platform where business logic and data integrity are paramount. We are looking for a Senior Engineer who can bridge the gap between complex system requirements and production-ready code.

RESPONSIBILITIES: 

• System Architecture: Lead the implementation of scalable backend patterns using NestJS. You will be responsible for enforcing Clean Architecture boundaries and transitioning monolithic modules into decoupled services where necessary.
• Database Stewardship: Lead the database restructuring initiative. You will design normalized schemas, plan migration strategies to minimize downtime, and optimize complex queries for performance at scale.
• Advanced Frontend Engineering: Architect the Next.js 14+ frontend application. You will define patterns for Server Actions, caching strategies, and reusable component composition to ensure high performance (Core Web Vitals).
• Technical Leadership: Establish coding standards, conduct rigorous code reviews, and mentor mid-level developers. You are the "Quality Gatekeeper."

Your skills and experience

Backend & Data

• Framework: Expert mastery of Node.js and NestJS. You understand the event loop, streams, and memory management deeply.
• Database: Advanced proficiency in PostgreSQL.

Frontend

• Framework: Expert knowledge of React.js and Next.js (App Router). You can explain the architectural trade-offs between SSR, CSR, and ISR in depth.
• UI Architecture: Ability to build complex, compound components using headless libraries (shadcn/ui, Radix UI) and Tailwind CSS.
• Performance: Experience debugging render cycles, memory leaks, and optimizing bundle sizes.

Tools & Workflow

• AI-Assisted Coding: You treat AI coding tools (Cursor, Claude) as a force multiplier. You know how to prompt for architectural patterns and rigorously audit the output for security and logic flaws.

Mindset & Work Ethic

• Product-Oriented: You don‘t just write code; you build products. You proactively identify gaps in the requirements and suggest improvements that align with business goals.
• Extreme Attention to Detail: You care about "invisible" quality—error handling, logging, data consistency, and edge cases. You assume things will break and code defensively.
• Outcome-Focused: You value shipping robust software over debating tools. You make pragmatic technical trade-offs and can articulate why you made them.
• Independent & High Agency: You can take a vague requirement like "Improve search accuracy" and turn it into a concrete technical roadmap without needing to be managed.
• Scientific Rigor: You don‘t guess; you measure. You use metrics and logs to prove your optimizations work.

Nice to Have

• Experience designing Microservices or Event-Driven Architectures (Kafka, Debezium).
• Experience with Monorepo tooling (Turborepo/Nx) in a production environment.
• Deep knowledge of Authentication protocols (OAuth2, OIDC) and security best practices (OWASP).

Why you'll love working here

• Social insurance coverage upon signing your employment contract.
• Generous leave policy: 12 annual leave days plus all Vietnamese public holidays.
• 13th-month salary (applicable from the probationary period).
• Company-provided equipment.
• Well-stocked pantry: tea, coffee, snacks, microwave, etc.
• Engaging company activities: Company trips, team-building events, regular internal events (including live music performances!), and access to company-sponsored badminton courts.