Skip to content
Backend & full-stack engineer

Maciej Fender

I build reliable web systems end to end — from data models and APIs to the interfaces on top of them. I care about clear boundaries, tests that document intent, and code that the next person can change without fear.

This site collects my projects and the technologies behind them, alongside a growing set of notes I keep while preparing for mid/senior technical interviews — part of a longer-running effort to get deliberately better at the craft.

Selected work

Systems, start to finish

all projects →

Ingests and aggregates millions of daily events at the edge, serving sub-second dashboards.

PythonFastAPIPostgreSQLRedisCloudflareDocker

Fan-out delivery service pushing in-app and web-push notifications with at-least-once guarantees.

PythonFastAPIRedisPostgreSQLDocker
The stack

What I build with

details →

Frameworks & libraries

Data stores

Infrastructure & cloud

Tooling

Practices

Interview prep

Notes on getting better

all topics →

Mid/senior technical questions I collect and refine while preparing. Pick a topic, then a subtopic, and expand the answers you want to test yourself on.