Senior Fullstack Engineer (LLMs & AI Agents)

Join; Warszawa; Hybrid; PLN 180,000 - 300,000; Full time

Benefits offered by this job

Remote-friendly setup

Job summary

Tappz is seeking a skilled engineer focused on AI systems and agent development to join our Warsaw-based team. You will design and ship backend systems powered by LLMs, build agent workflows, and optimize RAG pipelines in production.

We value ownership, speed, and the willingness to go the extra mile. Remote-friendly setup with opportunities to work on cutting-edge AI features in fast-growing startup.

Qualifications

• Strong backend and frontend engineering experience.
• Deep experience with LLMs and AI APIs.
• Experience building AI agents or multi-step workflows.
• Vector DB experience (Pinecone/Weaviate).
• RAG implementation and prompt engineering basics.

Responsibilities

• Design and build backend systems powered by LLMs.
• Develop agent workflows and tool integrations.
• Build RAG pipelines with vector search.
• Handle prompt orchestration and context management.
• Optimize performance, latency, and cost.
• Ship AI features into production products.

Skills

Backend engineering

LLMs

Agent workflows

Frontend engineering

Node.js

Next.js

Typescript

Python

Nest.js

GCP

Vector DB

Pinecone

Weaviate

RAG

Prompt engineering

System design

Production deployment

Tools

Pinecone

Weaviate

Job description

Location: Warsaw

Tappz is building AI-native applications powered by large language models. We’re moving fast in a highly competitive space and need an engineer who is fully focused on AI systems and agent development.

We’re looking for someone who enjoys high ownership, working hard, and shipping real AI products.

Tasks

• Design and build backend systems powered by LLMs
• Develop agent workflows and tool integrations
• Build RAG pipelines with vector search
• Handle prompt orchestration and context management
• Optimize performance, latency, and cost
• Ship AI features into production products

Requirements

• Strong backend and frontend engineering (Node.js, Next.js, Typescript, Python, Nest.js, GCP)
• Deep experience working with LLMs and AI APIs
• Experience building AI agents or multi-step workflows
• Vector DB experience (Pinecone/Weaviate/etc.)
• RAG implementation experience
• Prompt engineering and system design
• Production deployment experience

Mindset we value: Ownership, speed, and the willingness to go the extra mile

Benefits

High ownership in a fast-growing AI startup, remote-friendly setup, and the chance to build agent systems in production.