Zbigniew Mastylo

Principal Engineer & Tech Lead

Building scalable systems and mentoring high-performing teams

About Me

Zbigniew Mastylo

I build systems that scale, empower developers, and deliver real results.

I've led teams, built audit platforms, architected microservices, and released OSS like Rivusio and Zephcast.

I care about clean code, engineering culture, and moving fast without breaking clarity.

Based in Georgetown, TX. I am running on coffee, clean commits, and zero excuses.

My Journey

★ From Poland to Tech Leadership: A Story of Determination ★

Early Years in Poland

Growing up in Poland during martial law taught invaluable lessons about resilience and freedom. Living through political upheaval and economic hardship forged a determination to build a better future, no matter the obstacles.

My freedom was not free. It came with sacrifice, vigilance, and the courage to stand up for what was right in a time when speaking out carried real consequences. These formative experiences instilled a deep appreciation for liberty that continues to guide my decisions today.

Coming to America

Arrived in the United States with just $400, temporarily leaving behind a wife and 10-month-old son in pursuit of opportunity. What followed was a decade of consulting work, traveling across the country while finding ways to return home weekly or bi-weekly to maintain family bonds.

Every sacrifice was made with purpose and determination, always following the proper legal channels to secure a green card and eventually citizenship for the family.

Sacrifice and Perseverance

The path to securing a green card and eventually citizenship meant years of sacrifice and separation. Every step was taken by the book, following immigration laws while working tirelessly to build a foundation for family and future.

These challenges reinforced the value of persistence and the importance of long-term vision over short-term comfort. The journey wasn't just about changing location, but about creating lasting opportunity.

Education and Global Perspective

Earned two master's degrees in Computer Science and Mathematics. Collaborated with professionals from across the globe, gaining perspective and approaches that transcend cultural boundaries. This diverse experience has proven invaluable when building and leading engineering teams.

Working with people from various backgrounds and cultures has enriched both technical skills and leadership approach, creating a foundation for effective communication and problem-solving in diverse environments.

Professional Evolution

From startups to multi-billion dollar enterprises, each role has added depth to technical expertise and leadership philosophy. The journey has evolved from individual contributor to leader, coach, and mentor always with an emphasis on empowering others to achieve their potential.

This evolution has been guided by a commitment to excellence and continuous learning, adapting to new technologies and methodologies while maintaining core principles of quality and integrity.

Beyond Technology

Maintaining peak performance extends beyond professional life. Daily gym sessions, healthy nutrition, and periodic 7-day water fasts are part of a disciplined approach to physical and mental well-being.

A passion for high-performance driving and sports cars balances technical precision with exhilaration, with plans to pursue a racer's license. This commitment to excellence in all areas of life reinforces the same principles that drive professional success.

"The challenges we overcome define us more than our achievements. Every obstacle conquered becomes a foundation for future success."

What I Bring

  • Architecture across 80+ microservices and cloud-native platforms
  • Polyglot - Python, Java, C#, C++, C, shell scripting
  • FastAPI, AWS Lambda, S3, and Athena — building real-time audit and reporting systems
  • Secure API integrations with third parties — health tech, compliance, and reimbursements
  • OSS dev — creator of Rivusio (streaming) and Zephcast (messaging)
  • Mentoring, leadership, and building high-output teams that ship
  • Obsessed with performance, clarity, and shipping fast without breaking what works

Open Source Projects

Rivusio

Cutting-edge Python library for data streaming, transformations, and processing.

Python Data Processing Streaming Sync Async Parallel Processing

ZephCast

Lightweight, high-performance messaging library for RabbitMQ, Redis, and Kafka.

Python RabbitMQ Redis Kafka Messaging Sync Async

Some of What I've Built

Lesson Search System

AI-based search system for autistic children's school, streamlining teacher workflows and reducing search time by 10x.

Python AI Postgres pgvector SBERT

Lesson Recommendation System

AI-powered system recommending lessons for teachers working with autistic children based on learner summaries.

Python AI FastAPI Rivusio Docker

Session Notes System

AI system enhancing session log notes with behavior and lesson narratives for improved documentation.

Python AI FastAPI Docker Postgres

Modern Reporting Infrastructure

Polymorphic system for on-demand and scheduled reports with massive scalability and fault tolerance.

Python FastAPI AWS Lambda Step Functions S3

Data Warehouse

Fault-tolerant data pipelines and warehousing solution for a data startup, leading to 10x acquisition valuation.

Python Luigi Docker Postgres MySQL

Audit & Compliance System

Real-time audit platform with comprehensive reporting and compliance tracking.

FastAPI AWS Lambda S3 Athena

REST API Platform

Standardized API platform that reduced project delivery from weeks to days.

Python FastAPI Docker

Team Performance Transformation

Mentored engineering team and interns, boosting their velocity, morale and helping them become better humans.

Leadership Mentoring Agile

Enterprise Reporting System

Automated reporting system that saved $1.5MM/year by eliminating manual processes.

Python AWS Data Analysis

Active-Active Credit Card Refresh System

Redesigned system for real-time transactional data replication in active-active mode for a major bank.

HP NonStop C C++ DRNet

Long-Term Care Programs Testing Suite

Polymorphic system for testing long-term care programs, improving correctness and reducing validation time.

C# Azure MS SQL

High-Performance Search Tool

Delivered a fast and efficient compound curation & search tool, reducing search time by 10x.

Search Indexing Performance

Education & Patents

M.S. in Computer Science

University of Missouri, Columbia, MO

M.S. in Mathematics

Adam Mickiewicz University, Poznan, Poland

Patents

  • 8868527 - System and method for data processing
  • 7797422 - Network communication protocol
  • 7307985 - Distributed system architecture
  • 7293043 - Data management system

Get In Touch

Georgetown, TX