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Fullstack Developer

Digital Experiences with Passion and Precision

Let's work togetherBased in Jastrzębie-Zdrój, Poland
Bartłomiej Kosiński
Bartłomiej Kosińskicontact@bkosinski.dev
FrontendBackendMobileArchitectureAIFrontendBackendMobileArchitectureAIFrontendBackendMobileArchitectureAIFrontendBackendMobileArchitectureAIFrontendBackendMobileArchitectureAIFrontendBackendMobileArchitectureAIFrontendBackendMobileArchitectureAIFrontendBackendMobileArchitectureAI

AI Prototyping

Accelerating the validation of your vision. Using cutting-edge AI to rapid-fire prototype user experiences and technical benchmarks.

Innovation

The Shared Blueprint

The key to long-lived apps with many developers. Clear, maintainable insights that empower collaboration across the entire development process.

Documentation

Zero Surprises

The driver of customer satisfaction. Well-tested applications that run flawlessly, instill confidence, and never frustrate the user.

Testing

Architecting for Change

Building clean, adaptable structures that embrace new requirements. A scalable foundation that grows right alongside your business goals.

Architecture

Frictionless Delivery

Automating the path from code to production. Ensuring seamless, predictable deployments so features reach users faster and safer.

Automation

Uncompromising Speed

Optimizing execution to the millisecond. Delivering lightning-fast digital experiences that keep your users engaged and fully satisfied.

Optimization
Iamapassionatesoftwaredeveloperdedicatedtobuildingimpactfuldigitalsolutions.Ithriveonchallenges,balancingstrategicarchitecturewithhands-oncoding.Mygoalistocreatememorable,high-performancewebapplicationsthatmergestunningdesignwithflawlessfunctionality.

Precision Engineering

Building for the long term. Combining technical rigor with strategic foresight to deliver software that evolves as fast as your vision.

Type-safe
Structural Integrity
Eliminating the gap between intent and execution. Automated type-safety that ensures consistency across every layer of the system.
Performance
Millisecond Precision
Delivering speed where it matters most. Relentless optimization of the critical path to ensure lightning-fast interactions and industrial-grade efficiency.
Testing
Bulletproof Logic
Confidence built into every release. A high-coverage testing strategy that turns complex refactorings into routine updates without the fear of regressions.
Security
Fortified Core
Defense as a first-class citizen. Implementing hardened authentication and proactive monitoring to protect your assets before threats even emerge.

Technologies

Professional-grade tools and frameworks I've implemented in production environments to build robust, scalable, and high-performance applications.

JavaScript
TypeScript
React
Next.js
NestJS
Fastify
MySQL
PostgreSQL
Tailwind CSS
Sass
Docker
GitHub Actions

Recent Certificates

A list of my professional certifications and achievements.

NestJS Architecture & Advanced Patterns
Official NestJS CoursesOfficial NestJS Courses
Jan 2026
Credential
NestJS Advanced Concepts
Official NestJS CoursesOfficial NestJS Courses
Jan 2026
Credential
PRECISION ENGINEERING
STRUCTURAL INTEGRITY
HIGH-PERFORMANCE SYSTEMS
SCALABLE ARCHITECTURE
BEYOND BEST PRACTICES
PRECISION ENGINEERING
STRUCTURAL INTEGRITY
HIGH-PERFORMANCE SYSTEMS
SCALABLE ARCHITECTURE
BEYOND BEST PRACTICES
PRECISION ENGINEERING
STRUCTURAL INTEGRITY
HIGH-PERFORMANCE SYSTEMS
SCALABLE ARCHITECTURE
BEYOND BEST PRACTICES
PRECISION ENGINEERING
STRUCTURAL INTEGRITY
HIGH-PERFORMANCE SYSTEMS
SCALABLE ARCHITECTURE
BEYOND BEST PRACTICES
PRECISION ENGINEERING
STRUCTURAL INTEGRITY
HIGH-PERFORMANCE SYSTEMS
SCALABLE ARCHITECTURE
BEYOND BEST PRACTICES
PRECISION ENGINEERING
STRUCTURAL INTEGRITY
HIGH-PERFORMANCE SYSTEMS
SCALABLE ARCHITECTURE
BEYOND BEST PRACTICES

Bridging the gap
between humans and
digital experiences

For work:contact@bkosinski.dev
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