KB
Business web applications

Kacper Bernecki

Frontend / Web App Developer

I build business applications with React, TypeScript, Next.js and Supabase: CRMs, dashboards, forms, admin panels and tools that support company workflows.

I focus on practical web apps: lead management, user roles, forms, dashboards, automations and API integrations.

Kacper Bernecki professional portrait

About

I build practical web apps for business processes, not generic portfolio demos.

My strongest projects are operational web apps: CRM views, lead handling, role-based access, dashboards, forms and API-backed workflows.

I combine frontend work with enough backend and database context to build useful application flows end to end: Supabase auth, PostgreSQL data, server routes, validation and deployment.

AI tools are part of my workflow for prototyping, debugging and selected product features, but the core value is still application design, implementation quality and clear technical thinking.

CRM and workflow screens

CRM, dashboards, forms, admin panels and workflow tools.

Forms and typed UI

Component UI, typed logic, routing, state and form flows.

Roles and access

Auth, roles, lead data, history and database-backed screens.

Database and deployment

Vercel deployments, README/docs, CI and project roadmaps.

Context

Business workflow first, technology second.

01

Before writing code, I look at the process: who uses the app, what data they need, what changes status, and where the next action should be visible.

02

That approach is visible in B-CRM: role-aware sales and operations views, lead statuses, callbacks, meetings, comments, history and database-backed access rules.

03

The portfolio is organized around practical projects that can be inspected through live demos, repositories and case studies.

Application Focus

The recurring patterns in my projects are CRM workflows, dashboards, forms, data handling and integrations.

CRM and lead management

Lead lists, ownership, statuses, comments, callbacks, meetings and activity history.

Dashboard views

Operational screens with metrics, filters, rankings and clear next actions.

Forms and validation

Lead forms, admin forms, offer/calculation inputs and user-facing error states.

Role-based access

Different views and permissions for sales, management, finance, accounting, logistics and installation roles.

API and database work

Supabase, PostgreSQL, route handlers, serverless functions and external API calls.

AI as a tool

AI support for prototyping, debugging, automation and selected app features.

For companies and technical reviewers

Best project to review: B-CRM DEMO

Start with B-CRM DEMO if you want the fastest read on my web app skills.

Stack

React, TypeScript, Next.js, Supabase, PostgreSQL, Tailwind CSS, Vercel

What the project shows

  • Supabase authentication and protected app screens
  • User roles and permission rules for owner, admin, manager, sales and operational users
  • Lead management with statuses, comments, callbacks and meetings
  • Manager hierarchy, change history and activity-oriented CRM screens
  • Dashboards, filters, forms and database-backed workflows
  • Finance, accounting, logistics and installation realization flow
  • Deployment of a production-like web app demo on Vercel

Projects

A focused set of business apps and supporting web projects. B-CRM DEMO is the main technical proof.

01

B-CRM DEMO

B-CRM admin dashboard and demo workflow preview

Problem

Sales teams need one place to control lead ownership, status changes, callbacks, meetings and activity history.

Production-like CRM demo for lead management and sales workflow, built with role-based screens and Supabase-backed data.

Real features

  • Login and demo accounts
  • Roles: owner, admin, manager, sales, finance, viewer, accounting, logistics, installer
  • Lead statuses, comments and history
  • Callbacks, meetings and calendar views
  • Admin panel, team management and manager hierarchy
  • Realization tutorial: finance, accounting, logistics and installation
  • CSV import/export, PDF offer flow and KSeF demo payload

Demo credentials

Admin: demo / demo

Sales: demo-handlowiec / demo

Manager: demo-menadzer / demo

Stack

ReactTypeScriptNext.jsSupabasePostgreSQLTailwind CSSVercel

Status: Production-like CRM demo

02

Motomizer

Motomizer conceptual project artwork with product variants and gallery

Problem

A distinctive product with several functions needs a landing page that quickly explains what it does and lets visitors explore the available variants.

Responsive product landing page for a car-shaped aroma diffuser featuring exhaust-like mist, LEDs, engine sound and REV mode. Built around product presentation and availability enquiries.

Real features

  • Interactive colour selection: black, white and burgundy
  • Swipe-friendly product galleries and navigation
  • Dedicated feature, package and dimension visuals
  • Bilingual Polish and English website
  • Availability notification form
  • Mobile and desktop layouts

Stack

HTMLCSSJavaScriptResponsive UIVercel

Status: Public product landing / availability waitlist

03

StarCars Import

StarCars conceptual project artwork with car import cost dashboard

Problem

Importing a car from the US or Canada is complex: the auction bid is only part of the total cost, and customers need an understandable process and estimate.

Customer-facing site for US and Canadian vehicle imports, featuring interactive brand presentation, a landed-cost estimator, contact forms and a step-by-step journey from auction to delivery.

Real features

  • Import cost breakdown and estimator
  • Auction, origin-region, port and vehicle choices
  • Indicative USD/PLN exchange rate from the Polish central bank
  • Process, projects and FAQ sections
  • Enquiry form prefilled with cost context
  • Interactive 3D elements and animations

Stack

ReactTypeScriptViteThree.jsGSAPVercel

Status: Public business website / evolving

04

BeatMarket

BeatMarket conceptual project artwork with sound catalog and player

Problem

Producers and artists need a cohesive experience for discovering, previewing and licensing beats instead of fragmented file-sharing conversations.

An evolving beat marketplace with catalog discovery, audio previews, musical filters, producer pages, track submission and a licensing purchase flow.

Real features

  • Searchable beat catalog with sorting
  • Genre, musical-key and BPM-range filters
  • Audio previews and detailed beat pages
  • Producer profiles and track submission
  • Moderation before public listing
  • Licensing flow and developing payment integration

Stack

Next.jsReactJavaScriptSupabasePostgreSQLVercel

Status: Marketplace in active development

05

Interactive MacBook Portfolio

Interactive MacBook portfolio desktop preview

Problem

An interactive portfolio needs to stay playful without replacing the clearer technical evidence of the main site.

Experimental MacBook-style portfolio with a cinematic intro, desktop panels, project links, contact shortcuts and mini games.

Real features

  • Click-to-start MacBook intro
  • Interactive desktop with dock and app windows
  • Project, about, skills, contact and calendar panels
  • Terminal commands and quick actions
  • Embedded browser games and Berni Rush shortcut
  • ENG/PL language switch

Stack

ReactTypeScriptViteCSSlucide-reactVercel

Status: Experimental interactive portfolio

06

Berni Rush

Berni Rush browser game preview

Problem

A browser game project needs fast interaction, clear state handling and a playable loop rather than business workflow screens.

Playable 3D arena game prototype built to practice real-time interaction, state management and browser deployment.

Real features

  • 3D arena gameplay
  • Keyboard and touch controls
  • Playable classes and skins
  • Enemy waves and boss encounters
  • Upgrades, pickups and saved progress

Stack

ReactTypeScriptViteThree.jsZustandVercel

Status: Playable prototype / Side project

07

Portfolio

Portfolio homepage preview

Problem

A technical portfolio should help reviewers understand the strongest project quickly without entry-level positioning or vague marketing.

Personal developer site focused on business web applications, project evidence, bilingual case studies and protected email/phone reveal.

Real features

  • B-CRM-first project structure
  • Technical reviewer section
  • Bilingual case studies
  • Custom Cal.com booking flow
  • Protected email and phone reveal
  • SEO, OpenGraph and GTM-ready metadata

Stack

Next.jsReactTypeScriptTailwind CSSCal.com APITurnstileVercel

Status: Active development

08

Unreal Engine Gameplay Prototype

Unreal Engine gameplay prototype HUD screenshot

Problem

A gameplay prototype needs interaction systems, mission structure and environment blockout before it can become a full game.

Local Unreal Engine 5 prototype focused on gameplay systems, driving, contracts, UI/HUD and open-world environment exploration.

Note: Local prototype only: no public demo or repository.

Real features

  • Driving systems
  • Mission and contract mechanics
  • UI/HUD systems
  • Open-world environment blockout
  • Gameplay interaction systems
  • Performance and gameplay experimentation

Stack

Unreal Engine 5Blueprint SystemGame DesignUI SystemsOpen-world prototyping

Status: Local prototype / Experimental

09

Leasing Calculator

Leasing calculator business tool preview

Problem

Business users often need a quick leasing cost estimate before moving to a financial offer conversation.

Business calculator demo with leasing inputs, cost summary, printable result and lead capture flow.

Real features

  • Net and gross value handling
  • Down payment, period and buyout inputs
  • Operational/financial loan variants in UI copy
  • Result summary for the client
  • Lead form connected to a serverless endpoint
  • Business disclaimer for indicative results

Stack

ReactTypeScriptViteHonoDrizzleBunVercel

Status: Production-like business tool demo

Technologies used in projects

Stack used across projects and public demos.

React / TypeScript

Used in B-CRM, StarCars and BeatMarket, the leasing calculator and portfolio for UI components, forms, routing, state and app logic.

Next.js

Used for web app structure, routing, metadata, server routes and Vercel deployment.

Supabase / PostgreSQL

Used in B-CRM for auth, user roles, lead data, change history and database-backed workflows.

Tailwind CSS

Used to build responsive interfaces quickly across dashboards, forms and portfolio views.

Vercel

Used to deploy the portfolio, B-CRM and supporting public app demos.

OpenAI API

Used as a supporting tool for prototyping, debugging, automation and selected app features. AI is not presented as a replacement for software engineering skills.

Contact

Talk about a web app, CRM or frontend role

Find an available slot or reveal email and phone after a quick human check.

Calendar

Choose a day

Email

Phone

© 2026 Kacper Bernecki. All rights reserved.