About

Backend engineer focused on what code generation won't solve.

6 years of backend work on SaaS products, most of it in domains where the data has no clean source. Here's how I work and what I optimize for.

Krystian Jarmuł
Focus
Backend · Data · AI
Core
Python · Django · FastAPI
Experience
6+ years, SaaS products
Based
Poland · Remote

What I do

Backend for SaaS products: clean APIs, solid data models, async workers and the plumbing that keeps a system reliable as traffic grows. I have worked in HR, AdTech, AI search and GEO, fraud detection and telecom, and one thread runs through all of it - data acquisition. Crawlers, ETL pipelines and custom collection mechanisms for domains that offer no reliable structured source.

How I work

I default to boring, proven tools and make them ship outcomes. AI coding tools are part of my daily loop, which frees my attention for the parts they can't do: system design, domain understanding, architectural trade-offs. I write tests where they pay back, observability where it matters, and documentation only when the future-reader is someone other than me. I push back on premature abstraction.

Where I help most

Systems with a genuine data problem, where the source is messy, undocumented or simply absent. API-heavy products where the contract is the product. Teams scaling a Python codebase past the point where framework defaults are enough. AI features that have to be production-grade and trustworthy, not demos.

Outside the editor

Based in Poland, working remotely. When I'm not in code I'm usually outdoors, reading something non-technical, or stewarding the Manda brand that gives this site its character.