Spartan Dev

Overview of job

Build like a founder. Ship like Spartan.

Our customers are scaling fast and so are we. That’s why we’re looking for an Applied AI Engineer to join our world-class team.

At Spartan, we don’t act like contractors. We embed with startups backed by YC, Pear VC, BlingCap, 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 billions of requests.

This isn’t “just another AI role.” It’s a chance to work shoulder-to-shoulder with elite builders, solve complex startup challenges, and see your work directly drive companies raising millions on the global stage. You’ll also be at the frontier of AI: 70% of our portfolio is LLM-powered.

Key Responsibilities

• Prompts & Interfaces: Design clear prompt templates and role scaffolds (System/User/Assistant). Prefer structured outputs (JSON/schema).
• Context & Memory: Keep chats relevant with windowing/summarization and retrieval-backed long-term memory; basic tenant/privacy scoping.
• RAG Pipeline: Chunk/clean docs, embed into a vector store, run hybrid retrieval (BM25 + dense), and return answers with citations.
• Grounded Answers: Favor evidence, cite sources, and abstain when unsure.
• Agent Loops & Tool Use: Implement Plan → Act → Observe → Iterate; call APIs/DBs via typed tool contracts.
   

• 100% salary during probation
• Competitive compensation packages
• Unlimited PTO + public holidays
• Hybrid working model 
• Flexible working hours
• Macbook provided
• Premium healthcare insurance
• Social insurance in accordance with Labor Law
• Training and career development opportunities
• An open and transparent culture where people are valued, treated fairly, trusted, and empowered
• Sponsoring sports participation costs - We have play hours where our team meets up for PS5 Gaming and Football sessions, also with a Strava Yearly Subscription
• Challenging yourself with high and difficult goals by participating in unprecedented business models in the market.
• Working in an environment that is highly flexible and open, eager to incubate any valuable idea.

Growth at Spartan

• Mentorship from senior iOS and fullstack engineers
• Clear growth path from Junior to Middle to Senior iOS Engineer
• Work on real startup products, not internal demos
• Learn modern iOS, product thinking, and AI assisted development
• Every project feels like a small startup

Why Spartan

• More than 50 MVPs launched
• 3 IPOs and over $100M raised by our partners
• 95% engineer retention
• You will own real problems, ship real features, and grow fast