Applied AI Engineer (Junior - Middle, English)

Top 3 reasons to join us

• Competitive salary packages.
• Dynamic and open-sharing working environment.
• Hybrid and flexible working mode.

Job description

• 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.
  

Your skills and experience

• Fluent in English - you’ll talk directly with US startup founders.
• 1+ years building production features (AI, search, or backend). We’re language-agnostic.
• Solid grasp of LLM fundamentals: chat vs completion, roles, tokens/context, structured prompts.
• Hands-on with vector retrieval concepts (BM25, embeddings, HNSW/IVF) and basic grounding (citations/abstention).
• Comfortable integrating external/internal tools via function-calling or typed contracts.
• Strong CS fundamentals and a builder’s mindset - you own problems end-to-end.

• LLM & tooling: OpenAI, Anthropic, Google, Mistral, Llama • LangChain / LangChain4j, LlamaIndex
• Vector & search: Postgres/pgvector • Pinecone • Weaviate • Qdrant • Redis • Elasticsearch/BM25
• Data & messaging: Postgres • MongoDB • DynamoDB • Redis • Kafka • Pulsar • SQS
• Infra & ops: AWS • GCP • Azure • Kubernetes (k8s) • Terraform
• CI/CD & observability: GitHub Actions • Jenkins • DataDog • Prometheus • Grafana • ELK

Why you'll love working here

• 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