Julius Matheka
Charles
Software Engineer · Data Engineer · AI & ML Developer
Results-driven Software & Data Engineer with hands-on experience across the full data lifecycle — from pipeline design and SQL analytics to Python backend development and BI reporting. Building reliable, scalable systems with AI/ML integration.
About Me
Turning complex data into actionable insights and building reliable, scalable systems
I'm a Software & Data Engineer with hands-on experience across the full data lifecycle — from pipeline design and SQL analytics to Python backend development and BI reporting. I specialise in turning complex data into actionable business insights and building reliable, scalable systems.
With a Computer Science foundation and professional certifications in Software Engineering and Data Science, I've built a career across data engineering, backend development, and AI/ML integration — always focused on writing clean, maintainable code and delivering impactful solutions.
I bring a strong foundation in Agile delivery, cloud-native tools, and AI/ML integration. I'm always eager to take on new challenges and collaborate on projects that push the boundaries of what's possible.
Data Engineering
PostgreSQL · ETL/ELT · Airflow · Kafka · pgvector
AI / ML Integration
LangChain · OpenAI · RAG · Semantic Search · Claude
BI & Analytics
Power BI · Tableau · Dashboards · DAX · Data Modeling
Python Backend
Django · DRF · FastAPI · Celery · pytest
Years Experience
Professional Roles
Technologies Mastered
Commitment
Skills & Expertise
A comprehensive overview of my technical skills and proficiency levels
Data & SQL
BI & Analytics
Python
AI / ML
Frontend
DevOps
Key Projects
A showcase of my recent work in AI integration, data engineering, and full-stack development
Prepzi — Smart Meal Planning App
2025 – PresentAI-powered meal planning that reduces food waste by 90%. Generates personalized weekly/monthly plans from your inventory, with smart shopping lists, 10+ cuisines, dietary preferences, and offline-first sync.
LezMarket — AI Website Conversion Optimizer
2024SaaS tool that scores homepages against persuasion principles, generates AI recommendations, and stores structured analysis history per user.
Synovae — AI Job Matching Platform
2024Semantic CV-to-job matching engine across 2,400+ live roles using LLM embeddings, with automated application tracking in Supabase.
Work Experience
My professional journey in software development, data engineering, and BI analytics
Junior BI Developer
Design and maintain Power BI and Tableau dashboards surfacing KPIs across sales, operations, and finance — used weekly by senior management for decision-making.
Build and optimise SQL data models (star and snowflake schemas) in PostgreSQL to support fast, accurate reporting across multi-million-row datasets.
Translate stakeholder requirements into clear dashboard specifications; work iteratively with business users to refine metrics, filters, and visualisation layouts.
Implement data transformation logic using SQL CTEs and window functions to produce clean, business-ready reporting layers from raw transactional data.
Monitor dashboard data refresh schedules and pipeline health; resolve data discrepancies and communicate updates to stakeholders promptly.
Junior Python Data Engineer
Designed and implemented end-to-end data pipelines in Python and SQL — covering raw ingestion, staging, transformation, and analytics layers across PostgreSQL databases.
Built and scheduled Apache Airflow DAGs to automate recurring ETL jobs, replacing manual processes and improving data freshness for downstream consumers.
Engineered a semantic job-matching pipeline using Python, LangChain, and pgvector — parsing CVs and vectorising content for similarity search across 2,400+ live listings.
Implemented incremental loading patterns (upsert / ON CONFLICT DO UPDATE) and run logging to support efficient, restartable pipeline execution at scale.
Delivered a RAG-powered knowledge base using PostgreSQL/pgvector and LangChain, achieving sub-3-second query latency under load in production testing.
Junior Python Developer
Built scalable Python backend services and data ingestion scripts for small business clients — automating data collection from APIs and CSV sources into PostgreSQL.
Developed Django-based web applications with user authentication, role-based access, and data export functionality tailored to client reporting needs.
Integrated LangChain and OpenAI APIs to add AI-powered features including document summarisation, semantic search, and automated content generation.
Containerised applications with Docker and set up GitHub Actions CI/CD pipelines, enabling reliable and repeatable deployments across client environments.
Maintained 80%+ test coverage using pytest; resolved bugs and performance bottlenecks identified through production monitoring and client feedback.
Python Developer Intern
Developed and maintained RESTful APIs using Python and Django REST Framework, supporting internal data management tools used by operations teams.
Automated repetitive data extraction and file processing tasks using Python scripts, saving an estimated 10+ hours of manual work per week.
Assisted in integrating third-party APIs (payment gateways, CRM systems) into the core platform backend, handling data mapping and error handling logic.
Wrote unit tests using pytest, maintaining code coverage above 75% across all new modules developed during the internship.
Participated in daily Agile stand-ups, sprint planning, and code reviews — gaining hands-on experience with professional software delivery workflows.
Data Analyst Intern (SQL)
Wrote complex SQL queries across PostgreSQL databases to extract, clean, and analyse business datasets for weekly management reporting.
Built and maintained ETL pipelines that pulled data from multiple source systems into a central data warehouse, reducing manual data preparation time by 35%.
Created data quality checks using SQL (NULL validation, duplicate detection, row count reconciliation) to ensure pipeline integrity across all reporting tables.
Collaborated with senior analysts to design dashboard-ready summary views and aggregation tables consumed by Power BI reports.
Documented SQL query logic and pipeline steps, improving team knowledge sharing and onboarding efficiency.
Education & Certifications
My academic background and professional certifications
Education
Professional Certification — Software Engineering
Full-stack development, algorithms, Django/React, Java/Spring Boot.
Professional Certification — Data Science
Machine Learning, ETL pipelines, Python, SQL, TensorFlow, Tableau.
B.Sc. Computer Science
Strong foundation in algorithms, data structures, software engineering, and systems design.
Certifications
ETL and Data Pipelines with Shell, Airflow & Kafka
IBM
Data Warehousing and BI Analytics
IBM
Linux Commands and Shell Scripting
IBM
Get In Touch
I'm always open to discussing new projects, creative ideas, or opportunities to be part of your visions.