About
The story so far.
Sebastian "Tzezar" Drozd
Lead Backend Engineer & System Architect
I'm a developer who ships things. I started with Python and Django, went through React and the classic frontend journey, then found my groove in backend systems and TypeScript. These days I work mainly on event-driven architectures, data pipelines, and services that handle real volume, but I still love building UIs in Svelte when I get the chance.
I'm not a theoretical CS wizard with deep expertise in one niche. I'm a practical builder. When something needs to be built, I figure it out and ship it. I learn on the go, I use AI to move faster, and I focus on results over perfection. I ship open source that people actually use, and I focus on results over theory.
The Journey
Lead Backend Engineer & System Architect, Logisat
currentGPS fleet management platform. 40k+ tracked devices, ~1000 frames/sec. Designed the architecture, lead the backend team, own most of the services.
- Microservices & workers: GPS gateway, frames processor, event detector, geofencing, chat, notifications, geocoding, TCP multiplexer
- APIs & integrations: public API, internal APIs, ZSL gateway (KAS PUESC), tachograph ingestion
- Infrastructure: Terraform on AWS (ECS, MSK, RDS, ElastiCache), Docker, CI/CD, Grafana
- Superadmin UI in SvelteKit: charts, analytics, fleet management tools
- Shared packages, tests, benchmarks, documentation
Learning Break & Open Source
~2 yearsWent deeper into modern TypeScript ecosystem, picked up new frameworks and patterns. Started publishing open source: a headless datagrid and a component toolkit for Svelte.
Software Developer & Dept. Manager, Zaores (family company)
2017 – 2023 (maintenance since)Started on the warehouse floor (picking, delivery), got promoted to department manager & fleet supervisor. In parallel, built the company's entire digital infrastructure from zero:
- Full WMS/ERP/CRM system in TypeScript: inventory, multi-warehouse, invoicing, documents, customer management
- Physical server setup, WordPress e-commerce, self-hosted AI camera system (theft → 0)
- Grew email base 200 → 3k, 94% customer satisfaction, +31% employee satisfaction
Freelance Developer
2016 – present (on and off)Started freelancing as a teenager. Websites, e-commerce, client apps. Whatever people needed built, the stack evolved over the years as I grew.
Education
2019Stanisław Staszic Technical School, Computer Science Technician
Tech Stack
Backend & Systems
Infrastructure
Frontend (love this too)
Tools & Patterns
Open Source
3 packages on npm & GitHub
How I Work
// honest version
- I figure things out as I go. No task is too unfamiliar if the deadline is real
- Simplicity over cleverness. Complex systems should be built from simple parts
- Ship first, optimize where it hurts. Premature optimization is the enemy
- AI as a multiplier, not a crutch. I use it to go faster, not to avoid thinking
- Results over credentials. I don't have a CS degree, I have shipped software
Need something built?
Backend systems, data pipelines, Svelte frontends. If it needs to ship, I can help.
Get in touch