Senior Fullstack Engineer

• Design stable API contracts for internal screens and other engineers.
• Integrate payment, messaging, storage, and partner services, handling rate limits, retries, timeouts, webhooks, and production failure modes.
• Deliver features from API contract through to polished Next.js screens that cover all states.
• Build queue-based workers, background jobs, callbacks, notifications, imports, exports, and external-system syncs.
• Improve response shapes, caching, payload size, and web performance.
• Establish shared components and patterns across customer-facing and internal admin tools.

Key Success Indicators for this Role

• Delivers stable, well-designed APIs that internal product surfaces and other engineers can reliably build on.
• Ships end-to-end features that handle real-world states beyond the happy path.
• Improves the reliability and performance of integrations, asynchronous workflows, and web experiences.

Must Have

1. Professional Expertise (Hard Skills & Experience):

• 5+ years building and operating production web applications across APIs and browsers.
• Deep TypeScript experience; able to become productive quickly with Bun and Elysia.
• Strong API design judgment across resource modelling, versioning, pagination, error contracts, idempotency, and authentication.
• Experience with third-party and partner API integrations, including authentication, webhooks, retries, rate limits, timeouts, and production failure modes.
• Experience with queues, background jobs, and idempotent workers.
• Practical caching knowledge, including cache placement and invalidation.
• Self-sufficient SQL skills for modelling straightforward domains and writing queries.
• Security fundamentals: authentication, authorization, session and token handling, input validation, and common web attack surfaces.
• Deep Next.js and React knowledge, including server components, SSR, static rendering, and client rendering.

2. Communication & Documentation:

• Designs API contracts with the needs of their consumers in mind.
• Collaborates effectively across API and frontend work to deliver complete product experiences.

3. Personality & Behavioral Traits:

• Moves between backend and frontend work without friction.
• Takes ownership of features end to end and considers real-world states, not only the happy path.
• Cares about how the product looks and feels, closing gaps between mockups and production-ready screens.

4. Culture & Career:

• Contributes to shared components and product patterns that make future work faster and more consistent.
• Balances reliability, performance, and product quality across customer-facing and internal tools.

Nice to Have

• Experience with event-driven or queue-based distributed systems.
• Production experience with realtime transport such as MQTT or an equivalent pub/sub broker.
• Deep PostgreSQL knowledge, including query plans, indexing strategy, and schema migrations on live systems.
• Production experience with Redis, DragonflyDB, ClickHouse, or other data stores beyond PostgreSQL.
• Deep Next.js App Router knowledge, including server actions, streaming, caching, and revalidation.
• Experience with web performance tooling, including Core Web Vitals, bundle analysis, image optimization, and font optimization.

• 100% salary during probation
• Competitive salary + 13th-month bonus
• Annual salary review
• Premium health insurance from Bao Viet after probation
• Transportation support
• Lunch, coffee, and snacks
• All statutory benefits per Vietnamese Labor Law

Work Environment

• In-office, collaborative working environment
• Professional English-speaking workplace
• Supportive, fast-moving team
• Opportunity to build new product areas from the ground up
• Working time : 9am-6pm, Mon - Fri
• Working Location: The Sun Avenue, 28 Mai Chi Tho, Binh Trung ward, HCM City