Denys Krupka
Offer Denys work on your next project.
Private message 
Offer work 
Poznan,
Poland
28 days 10 hours back
available for hire
age 28 years
on the service 3 years
Rating
Successful projects
Average rating
Language proficiency level
Polski: fluent
Українська: fluent
Русский: fluent
English: pre-intermediate
Skills and abilities
Programming
Services
Mobile development
Portfolio
-
5026 USD Finkley — SaaS management accounting for beauty salons
Web Programming
Finkley — a niche SaaS application for management accounting for small beauty salons in the European Union (2–10 specialists: hairdressers, manicure, SPA, tattoo, cosmetology).
Problem: salon owners see client bookings in Booksy/Fresha but do not understand their actual profit after all expenses. They calculate once a quarter in Excel or in their heads.
Solution: one button → profit for the period. Tracking visits, expenses, calculating specialists' salaries, analytics. Without accounting jargon.
What has been implemented (solo, full-stack):
…
- Multi-tenant architecture with data isolation through Postgres Row-Level Security
- Auth: email, Google OAuth, Telegram Login
- Subscriptions and automatic VAT through Stripe + Stripe Tax
- Encryption of integration secrets (AES-256-GCM)
- Serverless backend on Supabase Edge Functions
- CI/CD through GitHub Actions, hosting on GitHub Pages
Stack: React 18 · TypeScript · Vite · Tailwind · shadcn/ui · Supabase (Postgres / Auth / Storage / Edge Functions) · Stripe · Sentry
The project is developed and maintained by one person from idea and architecture to production. GDPR compliance, data in the EU (Frankfurt).
#SaaS #ReactJS #TypeScript #Supabase #PostgreSQL #Stripe #FullStack #WebApp #FinTech #BeautyTech #Tailwind #StartupMVP
-
5291 USD MaxMaster Construction Platform — comprehensive SaaS platform
AI & Machine Learning
MaxMaster Construction Platform — a comprehensive SaaS platform for construction companies. It covers the full cycle of work for general contractors: from bidding and cost estimation to design, implementation, and financial calculations.
Implemented modules:
- Bidding — generation of commercial proposals for clients and requests to contractors, statuses, net amounts, validity periods
… - Estimates (Kosztorys) — full support for the Polish KNR database, hierarchical structure (sections/positions/norms), AI assistant for auto-filling positions
- Plans and drawings — built-in PDF viewer with measurement tools, layers, annotations, and versioning of project files
- Gantt chart — planning and tracking construction phases
- CRM — management of clients and contractors
- Finance and Supply — control of expenses and ordering materials
- HR module — Attendance, Vacations, Employee Schedules
- Document flow, Approvals, Reports
- Subscriptions — multi-tenant SaaS model with company administrator roles
Stack: React 19, TypeScript, Tailwind CSS, Supabase (PostgreSQL + Auth + Edge Functions + Storage), Google Gemini AI (project analysis and assistance in cost estimation), Recharts, Vite. Deployed at portal.maxmaster.info.
A real production product with active clients from the construction industry in Poland.
#saas #construction #buildtech #react #typescript #supabase #ai #erp
-
2116 USD Development of the SaaS platform MaxMaster Skills Platform
AI & Machine Learning
Development of a turnkey SaaS platform — from idea to production.
Case: MaxMaster Skills Platform — a competency and employee motivation management system for a Polish company. Addresses the HR department's task: assessment of employee skills, tracking growth, reward system based on actual competencies.
… Implemented:
- Web application with authorization and role model
- AI resume recognition module (Gemini) — saves HR hours of manual work
- Analytical dashboards for management
- Integration with Supabase: database, authentication, server functions
- Adaptive modern UI
Technologies: React 19, TypeScript, Supabase, Tailwind, Google Gemini API, Vite, PostgreSQL.
Ready to take on similar projects: SaaS, HR-tech, AI integrations, dashboards, systems with authorization.
#saas #react #typescript #ai #supabase #fullstack #mvp #startup
-
4762 USD KIK Pay — Telegram Mini App with virtual crypto cards
AI & Machine Learning
KIK Pay — Telegram Mini App (TWA) with virtual Visa/Mastercard crypto cards. A full-fledged web application inside Telegram in a cyberpunk aesthetic. It addresses the needs of crypto asset holders for regular online payments.
What has been implemented:
- Telegram Mini App with native integration into WebApp API
… - KIK Pay Wallet — user’s internal balance
- Issuance of virtual Visa/Mastercard cards ($2 per issuance)
- Top-up of cards with cryptocurrency
- Use of cards for online payments worldwide
- Personal account: Home, Wallet, Cards, Referrals, Settings
- Transaction history with filtering
- Referral program
- Side menu with navigation
- Custom UI/UX in Cyberpunk Edition style (dark theme, neon gradients, animations)
- Responsiveness for mobile Telegram screen
- Seamless authorization through Telegram (without login/password)
Technologies: React/Next.js, TypeScript, Tailwind CSS, Telegram Web Apps SDK, virtual card providers (Mercuryo/Wirex/analogues), integration with crypto wallets, REST API.
Part of the KIK ecosystem (along with KIK ExChange — the exchange) — a unified toolkit for crypto users.
#telegram #miniapp #twa #crypto #fintech #cards #react #typescript #saas
-
2116 USD KIK ExChange — Telegram bot of the cryptocurrency exchange
AI & Machine Learning
KIK ExChange — Telegram bot for a cryptocurrency exchange with maximum automation. It completes the full cycle of a transaction: from the client's request to cash delivery through a courier or exchange point.
What has been implemented:
- Exchange of cryptocurrencies for cash (USDT/BTC/ETH → USD/EUR/PLN)
… - Multichannel cash delivery: courier cash delivery, network of exchange points
- Automatic fixation of the exchange rate at the moment of request creation
- Full lifecycle of the request with statuses (created → confirmed → funds transferred → completed)
- Crypto cards — issuance and servicing of cards for crypto balance
- Referral program with a multi-level structure and auto payouts
- Client personal account: balance, request history, settings
- Rearrangement of funds between assets without withdrawal
- Repeat of the last operation in one click
- Multi-city model (shown in the screenshot — Warsaw)
- Separate interfaces for clients and operators
- Full localization for the EU market (PL/RU/EN)
Technologies: Python, Telegram Bot API, PostgreSQL, async I/O, Docker, integrations with exchange rate APIs (Binance/Bybit), KYC/AML modules, crypto card providers.
Real product in operation — request No. 18 in the screenshot shows a live transaction.
#telegram #bot #crypto #exchange #fintech #automation #python #saas
-
1058 USD BookySync Bot — Telegram bot
AI & Machine Learning
BookySync Bot — Telegram bot for automatic synchronization of salon business with accounting. It addresses a real pain point for salon owners in Poland: manual data transfer from Booksy to wFirma.
What the bot does:
- Automatic synchronization of visits from Booksy with an interval of ~30 minutes
… - Automatic entry of all expenses into wFirma (accounting system)
- Financial reporting — income, expenses, net profit
- Online profitability analytics in real time
- Telegram interface with buttons: Visits, Expenses, Status, Settings
- Notifications about synchronization status and connection errors
- History of synchronizations with success/error marks
Technologies: Python, Telegram Bot API, Booksy API (reverse-engineering), wFirma API, PostgreSQL, task scheduler (cron/celery), AI categorization of transactions.
#telegram #bot #automation #integration #api #python #booksy #wfirma #saas
-
1587 USD KIK Signals — Telegram bot
AI & Machine Learning
KIK Signals — Telegram bot for generating hot leads. It scans hundreds of Telegram groups in real-time and catches messages where people are actively looking for a specific service.
What the system does:
- Monitoring many Telegram groups simultaneously — both owned and others'
… - Multi-account architecture — parallel operation through multiple Telegram accounts
- Smart keyword filters with search template support
- Auto-search and auto-join in new thematic groups
- DRY-RUN mode — safe testing without sending messages
- KILL-switch — instant stop of all operations
- Statistics, lead history, sorting of best hits ("Hits")
- Inbox — centralized folder of all found leads
- Customizable response templates
- Full control panel in the Telegram interface
Technologies: Python, Telethon/Pyrogram (Telegram MTProto API), PostgreSQL, async I/O, Docker, multi-account session management, queue processing system.
Works for any country, city, and language. Reverse-engineering Telegram API (not Bot API — full access through user accounts).
#telegram #leadgen #automation #scraper #python #bot #saas
Activity
| Latest proposals 4 | Budget | Added | Deadlines | Proposal | |
|---|---|---|---|---|---|
|
Website of a multi-apartment building
2910 USD
|
|||||
|
Development of a language web application with learning logic, tests, and an admin panel
5672 USD
|
|||||
|
WooCommerce. Transfer products from a third-party site. Parsing.
200 USD
|
|||||
|
Development of a web and mobile platform for online booking with payment
9075 USD
|
