Principal Backend Engineer (AWS, TypeScript, DynamoDB)

Top 3 reasons to join us

• Competitive salary depend on your performance
• Working with young and passion employee
• Green and spacious office

Job description

About the role

Strong written and verbal English is a hard requirement for this role — please read on with that in mind.

You will own the backend that sits at the center of our business — the system of record for nearly everything the company does. This is the kind of role most engineers never get a shot at: a mature, high-throughput platform built on architectural choices that reward careful engineering, with real autonomy and consequential decisions to make. You are inheriting it, not building it from scratch, and you will be responsible for keeping it correct and fast while extending it.

You will initially work under the platform architect, with the explicit goal of growing into the architect role yourself. The work is hands-on and deeply technical, and you operate with a high degree of autonomy from day one.

What you'll work with

• AWS AppSync (GraphQL) — a single annotated schema compiled into multiple role-scoped APIs, backed by a large library of VTL resolvers and pipeline functions assembled through a custom build system.
• Amazon DynamoDB — single-table design with composite (PK/SK) keys, multiple GSIs, Streams, TTL, and PITR. The primary source of truth for the platform.
• AWS Lambda (TypeScript/Node.js) — many functions in an Nx monorepo, bundled with esbuild: API resolvers, queue consumers, stream processors, and Step Function tasks.
• AWS Step Functions — orchestration of multi-step workflows (order fulfillment, settlement/payout, lifecycle state machines).
• Event-driven processing — DynamoDB Streams, SQS, and Kinesis.
• Secondary data systems — Aurora MySQL, ClickHouse, OpenSearch, and Turbopuffer (vector/semantic search).
• Third-party integrations — Stripe, Pusher, Etsy, Amazon Cognito, and Sentry.
• Infrastructure as Code — Terraform/OpenTofu managing dev, test, and production.
• Testing — Jest (unit/integration) and Vitest end-to-end suites running against live AppSync APIs.

Responsibilities

• Work under the platform architect initially, with a clear path to taking on the architect role yourself as you build context and trust.
• Own the architecture, evolution, and reliability of the core backend repository and several related backend services — including a separate asset-generation service for image, PDF, and font pipelines.
• Design and extend DynamoDB access patterns — keys, indexes, and item layouts — treating schema and key-design changes as high-stakes, well-reasoned decisions.
• Build and maintain GraphQL APIs and their resolver pipelines, including VTL mapping logic and the supporting Lambda functions.
• Design event-driven and orchestrated workflows (Streams, SQS, Step Functions) that are idempotent, observable, and resilient to partial failure.
• Manage infrastructure through Terraform/OpenTofu; own safe, repeatable deployments across environments.
• Diagnose production issues to root cause — not symptoms — across the data, API, and integration layers.
• As the backend team grows, take on day-to-day technical leadership of less experienced engineers — mentorship, code review, and helping them ramp up on the platform's complexity.
• Uphold and extend a strong engineering documentation culture (architecture decisions, patterns, and gotchas are written down, not held in one person's head).

Your skills and experience

Required qualifications

• 10+ years of professional backend engineering experience (15+ preferred), with a substantial portion spent owning production systems at scale.
• Deep, hands-on AWS experience, including CI/CD pipelines and infrastructure managed with Terraform/OpenTofu.
• Strong NoSQL data-modeling expertise — direct experience designing single-table or composite-key models and the access patterns that ride on them, with a real understanding of the trade-offs involved.
• Production TypeScript/Node.js proficiency.
• Strong written and verbal English, including the ability to produce clear documentation and communicate effectively with stakeholders in other time zones.
• A demonstrated track record of full ownership: making sound architectural calls independently and being accountable for the result.

Strongly preferred

• AWS AppSync and GraphQL resolver experience (VTL a strong plus).
• Event-driven architecture and workflow orchestration (Step Functions, Streams, queues).
• Experience operating high-throughput, low-latency systems where data correctness is non-negotiable.
• Working experience with relational databases, search databases, and vector databases / embeddings.
• Image processing and color management for print (Sharp/ImageMagick, ICC profiles, RGB→CMYK).
• PDF internals, vector/SVG manipulation, and font engineering (pdf-lib, SVGO, fontTools/FontForge).
• Headless browser rendering (Puppeteer/Chromium) for high-fidelity output.
• Hands-on experience with AI agent orchestration, multi-agent workflows, and validation strategies — using harnesses like Claude Code or Pi to drive real engineering work, not just chat-style assistance.

Why you'll love working here

The opportunity

If you take pride in measuring twice and cutting once, reasoning to root cause, and writing down what you learn, this is the kind of system worth building a career around.

Why Join Corjl

• A high-impact role with real ownership over the core platform behind a growing product used by creators worldwide.
• A team that invests in great engineering — this is a leadership role, not a support role.
• Collaborative, engineering-driven environment based in Ho Chi Minh City.
• Competitive salary and benefits commensurate with experience.

How to Apply:

• Please submit your CV and links to recent work demonstrating your backend engineering capabilities. We are most interested in seeing your engineering thinking — include examples that show how you reasoned about a hard architectural problem, modeled data, and ensured correctness and reliability at scale. 
• Applications without relevant work samples or a clear account of systems you have owned will not be considered.