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Profile

Piotr Bujanowski PORTRAIT

PIOTR BUJANOWSKI

Backend / Full Stack Engineer

Location Philippines | Remote

Status Available now

Introduction

I build backend systems, business applications and automation. From design through to production.

I work on SaaS platforms, API integrations and payment systems. I also extend CRM tools and automate repetitive work.

I start by agreeing on requirements. I ship in stages and keep the codebase easy to extend later.

8+ Years experience
  • SaaS & backend
  • API integrations
  • Payments & CRM
  • Automation
Let's talk about your project

Contact

Remote work with clients worldwide

About

We define requirements, scope and delivery order together. I ship changes in small, verifiable steps and document technical decisions where it helps maintenance.

Working principles

  1. 1. Explicit module boundaries and responsibilities in code
  2. 2. Business rules in the domain layer, not in controllers
  3. 3. Staging and tests before production deployment
  4. 4. Queues, idempotency and automation for repeatable jobs

Technologies and tools

Programming languages PHP · Python · JavaScript (ES6+) · C++
Backend and frameworks Laravel (PHP) · Django (Python) · Flask (Python) · Node.js (JavaScript) · Ruby on Rails · Smarty
Frontend and mobile React · Vue.js · Angular · Tailwind CSS · SPA development · Flutter · Kotlin (Android) · Swift (iOS) · React Native
Databases and cache MySQL · PostgreSQL · MongoDB · SQLite · Redis
Automation and data Selenium · Playwright · Scrapy · requests / aiohttp · pandas · Proxy rotation and anti-bot techniques
Infrastructure Linux (server administration) · Nginx · Apache · Docker · VPS / cloud environments · Queue workers, Cron, Supervisor
APIs and integrations REST API architecture · Webhooks · OAuth authorization · Async and background processing
LLM integrations OpenAI · Claude · LLM workflows

Specializations

  • Backend systems & business applications

    Internal panels, operational modules and logic aligned with how the business runs.

  • APIs & external integrations

    Connecting client systems to partner services, webhooks and external platforms.

  • Payment systems & transactional flows

    Implementing and maintaining payment paths and settlement logic in business apps.

  • Process automation

    Replacing manual steps with scripts, queues and monitoring for recurring tasks.

  • Existing-system development & modernization

    Extending and modernizing existing systems with emphasis on stability, compatibility and limiting deployment risk.

  • Infrastructure & deployments

    Server configuration, containerization and production environment operations.

Selected Experience

  1. since 2018 (ongoing)

    Freelance Backend / Full Stack Developer

  2. 2023–2024

    Full Stack Developer / Infrastructure Administrator

    FlowSite

  3. 2021–2023

    Systems Developer / Infrastructure Administrator

  4. 2018–2023

    Game Developer / Platform Owner

Selected System Types

System Work
SaaS subscription platforms Backend architecture, subscriptions, permissions, REST API
Payment infrastructure Payment flows, billing, refunds, payouts, webhooks
Business CRM integrations Custom modules, APIs, queues, automation
Data automation Scraping, scheduled processing, monitoring, notifications

From project to maintenance

  • Architecture
  • Development
  • Integration
  • Deployment
  • Monitoring
  • Maintenance

Let's Talk

Have a project to build or extend?

I take on selected freelance and B2B engagements.

Tell me what you need. We can agree what I can help with and where to start.

Start a conversation