Senior Backend Dev ( AWS, JavaScript, NodeJS, GraphQL)

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’ll be a core contributor on the backend that sits at the center of our business — the system of record for nearly everything the company does. It’s a mature, high-throughput platform, and you’re joining a small team that owns it, working alongside the platform architect and a Principal Engineer. The work is hands-on and deeply technical, and you’ll be trusted with real components and features from the start.

This is a strong role for an experienced engineer who wants to do real work on a real system: meaningful ownership over what you ship, exposure to architectural decisions, and a clear path to expanding scope as you build context and earn trust.

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

• Build, extend, and maintain features across the core backend repository and related backend services.
• Implement GraphQL APIs and their resolver pipelines, including VTL mapping logic and the supporting Lambda functions.
• Work with the existing DynamoDB access patterns and indexes — extending them carefully and flagging when a change has broader implications.
• Build event-driven and orchestrated workflows (Streams, SQS, Step Functions) that are idempotent, observable, and resilient to partial failure.
• Diagnose production issues across the data, API, and integration layers — reasoning to root cause, not symptoms.
• Make infrastructure changes through Terraform/OpenTofu when your work requires them.
• Participate in code review and design discussions; raise alternatives and trade-offs rather than just executing.
• Contribute to and uphold the team’s documentation culture (architecture decisions, patterns, and gotchas get written down).

Your skills and experience

Required qualifications

• 5+ years of professional backend engineering experience (7+ preferred), with significant time in production systems on AWS.
• Hands-on AWS experience across core serverless and data services — Lambda, DynamoDB, IAM, SQS, S3, CloudWatch — and comfort working with infrastructure managed by Terraform/OpenTofu.
• Working knowledge of DynamoDB and NoSQL data modeling — composite keys, GSIs, access patterns — with an understanding of why those choices matter at scale.
• 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 track record of shipping reliable production code and taking responsibility for the work you put your name on.

Strongly preferred

• AWS AppSync and GraphQL resolver experience (VTL a plus).
• Event-driven architecture and workflow orchestration (Step Functions, Streams, queues).
• Experience operating systems where data correctness and reliability matter — payments, ordering, anything money-touching.
• Working experience with relational databases, search databases, or vector databases / embeddings.
• Image processing and color management for print (Sharp/ImageMagick, ICC profiles, RGB→CMYK).
• PDF internals, vector/SVG manipulation, or 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

A chance to do serious engineering on a serious system, alongside people who care about getting it right and care about helping you grow. If you sweat the details, debug to root cause, and want to keep getting better at this, it’s a good place to do that.

Why Join Corjl 

• A high-impact role with real ownership over the core platform behind a growing product used by creators worldwide. 
• 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.