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ABOUT ME

Who I am

AI Engineer specializing in building production LLM systems. From prototype to production — I build AI systems that solve real business problems with documented ROI.

My mission

I believe AI should be accessible and practical. I specialize in transforming advanced language models into reliable production systems. I approach every project with an engineering mindset — measurable results, full observability, and cost optimization.

My approach

I don't build demos — I build production-ready systems. That means: automated evaluations, input and output guardrails, real-time monitoring, and architecture that scales with the business. Every system is designed with maintainability and costs in mind.

Experience

Where I worked and what I did

Project Manager
Open Technologies · Full-time
Jan 2021 — present

Delivered product development and operational projects valued at up to 500k PLN.

  • Leadership: Led cross-functional teams of 10+ members across international markets (DACH region)
  • Expansion: Managed business expansion into Asian markets and established strategic partnerships
  • Optimization: Reduced operational costs and improved team efficiency through data-driven KPI tracking
Independent AI Application Engineer
Remote
May 2025 — present

Prompt optimization and AI integration consulting for business clients. API cost reduction and improvement of model response quality.

  • Prompt optimization for GPT-4 and Claude
  • Implementing guardrails and response validation
  • Team training in prompt engineering
  • Audit and optimization of existing AI systems

Education & Certificates

Continuously growing in the AI field

Building Generative AI-Powered Applications with Python
IBM
Building AI applications with Python, LLMs, and APIs
02 / 2026
Python for Data Science, AI & Development
IBM
Python, API, Machine Learning, JSON, Data Science
01 / 2026
Generative AI: Introduction and Applications
IBM
Fundamentals of generative models and business applications
10 / 2025
Generative AI and LLMs: Architecture and Data Preparation
IBM
LLM architecture and data preparation
2025

Skills

Technologies and tools I work with daily

AI & LLM

LangChainOpenAI APIAnthropic ClaudeRAG SystemsPrompt EngineeringLLM Evaluations

Backend

PythonFastAPIRedisPostgreSQLCeleryWebSockets

Frontend

TypeScriptNext.jsReactFramer MotionTailwind CSSThree.js

DevOps & MLOps

DockerAWSLangSmithPrometheusGrafanaCI/CD

Databases

PineconeWeaviateChromaDBUpstash VectorSupabaseMongoDB

Projects

Production AI systems solving real problems

RAG Q&A System

Hybrid search system combining semantic and keyword search for accurate AI answers. Full observability with LangSmith and real-time metrics.

40%
fewer hallucinations
LangChainPineconeFastAPILangSmith

LLM Evaluation Framework

Automated LLM model evaluation pipelines — measuring accuracy, relevance, and safety. Testing system with 50+ test cases and 4-layer protection.

60%
lower costs
PythonOpenAIPytestGuardrails

Production LLM Architecture

Complete systems from document ingestion to real-time monitoring. Asynchronous processing with Redis cache and sub-second responses.

1000+
daily users
FastAPIAsyncTracingRedisPrometheus

Intelligent Chat Interface

Smart caching layer reducing API costs while maintaining sub-second responses. RAG with vector search and contextual conversation memory.

50%
cost reduction
Next.jsRedisOpenAIUpstash Vector
Let's talk
© 2026 Jakub Prejzner
System v2.0 | 2026