~/kslomka
open to architect roles & consulting

Krzysztof Słomka

I build backend systems that have to keep working.

Senior Backend Engineer & Software Architect · distributed systems · DDD · event sourcing · Kraków, Poland

Work with me Download CV
years shipping backends
15+
years shipping backends
payments · factoring · lead generation
fintech
payments · factoring · lead generation
articles on the blog
53
articles on the blog
kisztof — -zsh — 80×24

$

it's a real shell — try help, or read the blog.

about

I build backend systems that have to keep working.

Fintech platforms, payment APIs, SaaS products, high-traffic web apps. Fifteen years of it, mostly in payments, factoring, and lead generation. My focus is backend architecture, distributed systems, event-driven design, and the platform engineering around them: cloud-native services on AWS and GCP, API design, observability, analytics pipelines. Also the unglamorous job of modernizing backends nobody wants to touch. I'm backend-first, but I ship whole products when the job needs it, with React, Next.js, Svelte, or Electron on the other side.

AI changed how I work more than any tool I picked up in the last decade. I wrote down how I use it, and where I still don't trust it, in my AI manifesto →

skills

AI Engineering

06
AI AgentsLLM IntegrationsMCPAgentic WorkflowsDeveloper ExperienceWorkflow Automation

Architecture

07
Software ArchitectureDistributed SystemsEvent-Driven ArchitectureCQRSDDDMicroservicesModular Monolith

Languages

05
PHPTypeScriptJavaGoKotlin

Frameworks

05
SymfonyNestJSNode.jsSpring BootLaravel

Frontend

05
ReactNext.jsTailwind CSSSvelteElectron

Cloud & DevOps

09
AWSGCPAzureKubernetesDockerCI/CDGitHub ActionsGitLab CIJenkins

Data & Messaging

05
PostgreSQLBigQueryOpenSearchElasticsearchRabbitMQ

Platform Engineering

05
ObservabilityAPI DesignCloud-Native SystemsFintech SystemsBackend Development

experience

$ git log --graph --career

552cc18 · Nov 2013 — present

(HEAD -> main, tag: own-company)

Irbis Software

Kraków, Poland

Business Owner

  • Independent B2B consulting and software development projects focused on backend systems, automation, and custom business platforms.
  • Architecture advisory, backend engineering, and DevOps setup for small and mid-size teams, run alongside contract engagements.
  • AI-assisted engineering workflows and LLM integrations: agent tooling, MCP-based automation, and internal knowledge systems layered on existing codebases.
TypeScriptNestJSPHPSymfonyGoAWSAI AgentsLLM Integrations+ Node.js, Java, Spring Boot, PostgreSQL, Docker, CI/CD

b3ff5a3 · Apr 2023 — May 2026

Excel Impact

Miami, FL, USA (Remote)

Senior Software Engineer

  • Led migration of legacy backend services from PHP to NestJS and TypeScript, improving scalability, maintainability, and operational visibility.
  • Designed distributed backend services and APIs for high-scale lead-generation and fintech-related platforms.
  • Designed platform architecture, observability tooling, event tracking systems, and BigQuery-driven analytics pipelines.
  • Built backend debugging workflows using OpenSearch, structured logging, and operational monitoring.
  • Improved engineering standards across services: project structure, documentation, logging strategies, best practices.
  • Conducted backend performance audits and optimization initiatives, improving reliability and developer experience.
TypeScriptNestJSPHPSymfonyAWSGCPPostgreSQLBigQuery+ Redis, OpenSearch, Kubernetes

c2cdc4c · Feb 2024 — Nov 2024

Volt.io

Cracow, Poland (Remote)

Senior Software Engineer

  • Designed secure backend services and payment-related APIs for fintech and open banking solutions.
  • Contributed to a global payment API gateway supporting payment initiation and processing across regions and banking providers.
  • Improved distributed payment systems for scalability, low latency, reliability, and fault tolerance.
  • Applied CQRS, DDD, and distributed-systems principles in production fintech environments on AWS.
PHPSymfonyAWSCQRSDDDDistributed Systems

7a8c8c2 · Dec 2022 — Apr 2023

Ibexa

Kraków, Poland (Remote)

Senior Software Engineer

  • R&D for Ibexa DXP; built REST APIs and backend services for third-party integrations and enterprise extensibility.
  • Ran architectural evaluations jointly with product and engineering teams on modernization opportunities.
PHPSymfonyREST APIsDockerPostgreSQL

33a0a01 · Jun 2018 — Dec 2022

PragmaGO.tech

Kraków, Poland

Software Architect

  • Designed distributed architecture for fintech platforms and backend services focused on scalability and high availability.
  • Designed microservice-based systems, integration layers, communication contracts, and event-driven solutions.
  • Led architectural initiatives across teams: engineering standards, code quality, mentoring, technical documentation.
  • Designed and optimized CI/CD pipelines and containerized environments (Jenkins, GitHub Actions, Docker, Kubernetes).
PHPSymfonyLaravelTypeScriptNestJSJavaKotlinSpring Boot+ PostgreSQL, RabbitMQ, Kubernetes, Docker, GCP, Azure

earlier — git log --oneline

PragmaGO.techSenior Software Engineer2015
  • Built backend services and financial modules for fintech/factoring: settlement, reconciliation, reporting, integrations.
  • Designed backend architecture, APIs, async workflows, and integration layers using PHP and Node.js.

PHP, Symfony, API Platform, Node.js, TypeScript, PostgreSQL, RabbitMQ, ElasticSearch, Jenkins

TVNSoftware Engineer2014
  • Built high-traffic backend for TVN24biz, a large-scale CMS handling millions of articles and media assets.
  • Contributed to an internal CMS built with Symfony, improving editorial workflows and search capabilities.

PHP, Symfony, MySQL, JavaScript, Jenkins

AKRA PolskaPHP Backend Engineer2013
  • Built backend applications and custom web platforms for e-commerce and business-oriented solutions (key2print.pl, wszycyklikamy.pl).

PHP, Symfony, Laravel, Zend Framework, Sylius, MySQL

Ezotic.plTeam Leader2013
  • Led a small development team for backend and billing systems for enterprise clients.
  • Designed and implemented a billing and integration system for Energa S.A.

PHP, CakePHP, MySQL, JavaScript, UML

Rise AgencyWeb Developer2012
  • Developed custom web platforms and CMS-based solutions for clients including Royal Canin and Fenix Group.
  • Built couponing systems and product-finder applications tailored to client requirements.

PHP, Symfony, MySQL, JavaScript, jQuery

FreelanceFreelance Web Developer2008
  • Delivered custom websites and web applications for small businesses and individual clients.
  • Managed Linux-based hosting environments and production deployments.

PHP, MySQL, Linux, JavaScript

projects & writing

Driftr

open source

Node.js, pnpm, yarn and bun version manager written in Go, built to replace Volta. Resolves versions through shims, reads existing .nvmrc and packageManager pins, and verifies every download.

GoCobraTOML
github.com/StackMade/Driftr

gtm-as-code

open source

Google Tag Manager and GA4 configuration declared in YAML and applied Terraform-style: plan the diff, review it in a pull request, deploy it from CI instead of clicking through the GTM interface.

TypeScriptNode.jsCLI
github.com/StackMade/gtm-as-code

StackMade

product

My studio for digital products. Websites, web applications, AI-powered software, and the backend systems behind them.

Web AppsAI & AutomationBackendCloud
stackmade.pl

PoliczProsto.pl

product

Nearly sixty Polish calculators for tax, salary, loan and business questions, plus 81 salary-amount pages, monthly rankings of deposits, savings accounts and mortgages with CSV downloads, and Elixir session times for 13 banks. All statically prerendered; every statutory rate lives in one file, so a change in the law is one edit.

policzprosto.pl

lepszaenergia.pl

product· client work

Site for a renewable-energy company in business since 2003, told as one continuous story in nine cinematic chapters. Static export on shared hosting, company data in one config file, plus the brand book, mark and business-card generator.

Next.jsGSAPStatic export
lepszaenergia.pl

v2project.pl

product· client work

Site for an engineering office designing photovoltaic and power infrastructure. The old one was a client-rendered SPA invisible to search engines: empty root div, no robots, no sitemap, no structured data. Rebuilt server-rendered, with the brand around it.

Next.jsThree.jsGSAP
v2project.pl

LabelBite

product· coming soon

An iPhone nutrition tracker that reads food labels on the device. Point the camera at a nutrition table, check the values, log the portion. No account, no server, no analytics.

SwiftSwiftUIVisioniOS
labelbite.app

Fluxfer

product· pre-release

A dual-pane SFTP, FTP and FTPS client for macOS that counts a transfer as done only when the server confirmed it. Persistent queue, resume and crash recovery, secrets kept in the Keychain only.

SwiftSwiftUIAppKitlibssh2
fluxfer.stackmade.pl

Tilter

product· coming soon

The iPhone Duo effect on your Mac. A menu bar app that reads the MacBook lid-angle sensor and folds the screen away as frosted glass while you close the lid. Native Swift and Metal, coming to the Mac App Store.

SwiftMetalmacOS
tilter.app

stackurl

product

A link shortener with no database: the URL is compressed with arithmetic coding and the compressed bits are the link, so it resolves anywhere and never expires.

stackurl.plurlz.pl →

YouTube

channel

Videos on the engineering work behind the posts: agent tooling, architecture, and the setups I actually run, recorded end to end.

▶ Give your coding agent memory: Serena + Graphify + Obsidian, set up from scratch♪ @dev-records: music for developersyoutube.com/@kisztof
more on GitHub →

$ ls -lt ~/blog | head -5

all posts →

contact

Got a system that has to keep working? Let's talk.

krzysztof@slomka.pro

Hiring

Open to Principal / Senior Backend Engineer, Software Architect, and AI Platform / Developer Experience roles, remote-first.

Download CVConnect on LinkedIn →

Consulting

Available for consulting on AI-assisted engineering workflows and agentic tooling.

Read my AI manifesto →See what I use →

© 2026 Krzysztof Słomkaprivacyterms