PL · Polska wersja

Marcin Jarema

Junior Data Analyst | Production Planning & Reporting | Power BI / SQL / Excel
marcinjarema0802@gmail.com +48 530 106 409 Opole, Poland github.com/MarcinJarema linkedin.com/in/marcin-jarema
Marcin Jarema

Professional Summary

Data Analytics in Business student at Opole University of Technology (part-time studies, graduating 02.2027). Since 09.2026 I work as a Junior Production Planning Specialist at Aluprof S.A. I build reports and dashboards in Power BI (star schema, DAX), work in Excel (including VBA), SQL and Python, and in personal projects I combine data analytics with AI-based systems (RAG, LLM agents). I am looking for a data analyst / BI / reporting role where accuracy, working with data and process documentation translate into business decisions.

Technical Skills

Data Analysis & Reporting

  • Power BI: star schema, DAX measures, KPIs, tooltips, navigation
  • Excel: advanced (pivot tables, Power Query), VBA
  • SQL: queries, aggregations, optimisation (PostgreSQL)
  • Studies: statistics, data warehousing, Business Intelligence

Data Preparation & Tools

  • Python: Pandas, ETL, web scraping, yfinance
  • Databases: PostgreSQL (pgvector), SQLite, Qdrant
  • Tools: Git / GitHub, Docker, REST API (FastAPI)
  • Quality: testing (pytest), linting (ruff), documentation

AI & Languages

  • LLM / RAG: LangChain, LangGraph, embeddings, prompt engineering
  • AI in daily work: Claude Code, Gemini (AI-assisted development)
  • English: C1
  • Strengths: accuracy, analytical approach, fast learning

Projects

Bitcoin Halving Market Impact
Repository
Python yFinance Power Query Power BI DAX
  • Goal: describe how BTC, ETH and selected US stocks behaved in ±550-day windows around the 2016, 2020 and 2024 halvings.
  • Built a star-schema model (fact and dimension tables) with DAX measures and a multi-page Power BI report with navigation, drill down / drill through, custom tooltips and custom visuals.
  • Added in-report documentation and a help page; data downloaded in Python (yfinance) and prepared in Power Query. The project is descriptive, with no causal claims.
Equity Research Agent
Repository
Python LangGraph FastAPI pgvector Docker
  • Built an equity analysis agent (router → tools → synthesis graph) with market data, metrics and news tools and RAG on PostgreSQL with pgvector.
  • Quality focus: metrics calculated in code rather than by the LLM, LLM-as-judge evaluation, observability in LangSmith, pytest tests, ruff linting, everything in Docker Compose.
  • Educational project, not investment advice.
AI Assistant (RAG) for ClickJobs.pl
Repository
Python FastAPI LangChain Qdrant TypeScript
  • Implemented the backend of an AI assistant (RAG) with a Qdrant vector database, local embeddings and a swappable LLM provider.
  • Secured the solution: prompt-injection filter (PL + EN), rate limiting, cost control, anonymisation of personal data (GDPR).
  • Delivered an embeddable widget (TypeScript, Shadow DOM, white-label) and a Docker environment.
Opole Traffic ETL
Repository
Python Flask SQLite Docker pytest
  • Automated a real-time ETL pipeline: data from 3 locations in Opole every 15 minutes (TomTom API + weather scraping), SQLite database.
  • Designed a custom jam_factor metric (0–10) and a map dashboard (Flask + Leaflet.js).
  • Quality focus: 22 automated tests (pytest) and Docker Compose deployment.

Professional Experience

Junior Production Planning Specialist
Aluprof S.A., Opole
09.2026 – present
  • I write step-by-step instructions (with screenshots) for processes in the Tarkus system, standardising ways of working in a newly created planning department.
  • I work with production order data and organise process documentation.
Intern — AI / Backend Developer
ClickJobs.pl
22.06.2026 – 22.08.2026
  • Implemented an AI assistant (RAG) from scratch in a structured company environment, with ongoing documentation and reporting of results to the supervisor.
  • Internship completed with a certificate and a reference.
Career Office Ambassador
Opole University of Technology
10.2024 – present
  • Supporting the organisation of Job Fairs and regular contact with companies (B2B).
  • Working with many people at once and presenting information to different audiences.
Security Staff (Work & Travel)
Camp Greylock, Massachusetts, USA
06.2025 – 09.2025
  • Day-to-day communication in English (C1) in an international team.
  • Working to procedures under time pressure.
Machine Operator (seasonal job)
EHG Edelstahl Rohrherstellung GmbH, Germany
06.2022 – 08.2022
  • Operating an overhead crane and repairing electrical machines on a stainless steel pipe production line.
  • Reviewing technical documentation and reporting production status and quality deviations to management.

Education

Opole University of Technology
10.2024 – present (graduating 02.2027)
Field of study: Data Analytics in Business (Bachelor of Engineering, part-time studies)
Python, SQL, statistics, data warehousing, Business Intelligence, business processes.
ZSP nr 1 in Praszka (secondary technical school)
2018 – 2022
Qualification: Mechatronics Technician