Full-Stack Engineer

Build like a founder. Ship like Spartan.
Our customers are scaling fast - and so are we. That's why we're looking for a Fullstack Engineer (React/TypeScript) to join our world-class team.
At Spartan, we don't act like vendors. We embed with startups backed by YC, Pear VC, a16z, Techstars, and more - partnering with founders and engineers from Stanford, MIT, Yale, Google, Amazon, Uber, and beyond. Together, we help launch MVPs in 30 days and scale systems that power millions of users.
This isn't "just another engineering role."
It's a chance to build across the stack, craft intuitive user experiences, and design scalable backend systems - seeing your work directly power companies raising millions on the global stage.
You'll also be working at the frontier of AI: 70% of our portfolio today is LLM-powered. Our engineers leverage the latest tools like Cursor, Claude, and Codex to accelerate development and integrate AI-native workflows into everything we build.
What You'll Do
Build scalable, reliable, and beautiful fullstack applications with React, TypeScript, and [protected info]
Work directly with US startup founders and product leaders - shaping solutions that drive their business forward.
Ship fast with a proven process: async standups, PRDs/RFCs, code reviews, automation.
Work in an AI-native workflow - leveraging tools like Cursor, Claude, and Codex to reduce boilerplate and boost iteration speed.
Uphold engineering excellence - clean code, testing, documentation, reliability.
Help shape Spartan's engineering culture - we're 1% pass-rate engineers who work like founders, not contractors.
What We're Looking For
Fluent in English - you'll work directly with US startup founders.
3+ years building production-grade applications.
Strong expertise in React, TypeScript, and modern JavaScript (ES6+).
Solid backend experience ([protected info], [protected info], APIs, databases).
Knowledge of frontend fundamentals: state management, performance optimization, accessibility.
Experience with design systems, responsive UI, and API integrations.
A builder's mindset - you care about solving problems, not just writing code.
Tech We Use
Every project brings a different stack, so in a year here you'll touch more of this list than most engineers do in five. What we adopt is decided by our engineers through an internal Tech Radar, not handed down from a slide deck.
Languages: Go
Java/Kotlin/Scala
TypeScript
Python
Data: Postgres
MongoDB
DynamoDB
ElasticSearch
Redis
LLM stack: Claude API
OpenAI API
MCP
LangGraph
LangSmith
Vector search: pgvector
Pinecone
Qdrant
Weaviate
Streaming: Kafka
Pulsar
SQS
AWS Kinesis
GCP Cloud Tasks
Data processing: Spark
Flink
Cloud: AWS
GCP
Azure
Kubernetes
CI/CD: Jenkins
GitHub Actions
Observability: DataDog
Prometheus
Grafana
ELK Stack
AI tooling: Cursor
Claude
Codex
Career Growth
Work directly with founders from YC, Stanford, MIT, Yale, Google, Amazon, Uber, and more.
Exposure to LLMs, AI agents, cloud infra, and real-time systems.
Transparent career path and mentorship from engineers who've taken 3 companies to IPO.
Every project feels like its own mini-startup.
Why Spartan
50+ MVPs launched, 3 IPOs, $100M+ raised by the startups we build with.
95% engineer retention. People stay because the work is worth staying for.
You build zero to one. Blank repo to live product in weeks.
Most engineers get that chance once in a career. Here it's the job.
Your work is visible. What you ship this month is in a founder's investor demo next month.
No layers, no bureaucracy.
You talk to the decision-maker directly, and decisions land in hours, not weeks.
Every project is a new market, a new stack, a new problem. One year here teaches what three years elsewhere would.
You'll never just take tickets. You'll own problems, ship fast, and grow with the founders we partner with.
Benefits &
Perks
💰
Competitive salary, 100% salary during probation
🏝
Unlimited PTO + public holidays
🩺
Premium healthcare insurance + annual health check
⚽
Sports clubs for every taste: football, badminton, billiards, pickleball
🎮
PS5 and Nintendo at the office
🏃
Strava yearly subscription
🏠
Hybrid working style, flexible hours
✈️
Annual company trip + monthly team parties
💻
MacBook provided
📜
Social insurance per Labor Law
Work Location
HCM: 2nd Floor XL Building, 167 Tran Nao, An Khanh Ward
Da Nang: 2nd Floor, 458 Nguyen Huu Tho, Cam Le Ward