Freelance Backend Engineers in Warsaw

Freelance Backend Engineers in WarsawFreelance Backend Engineers in Warsaw

Projects People

pro

Full-Stack Engineer | Replit & Cursor | AI Integration

5.0: Rating

23: Followers

expert

Full-Stack Engineer | Replit & Cursor | AI Integration

Cover image for OMA Health Marketing Website Development

OMA Health Marketing Website Development

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1

Cover image for Stripe Payment Webhook Integration

Stripe Payment Webhook Integration

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1

Cover image for CRUD API Workflow (Create Record) with Buildship

CRUD API Workflow (Create Record) with Buildship

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2

Cover image for Founder Portfolio — Product Builder & Co-Founder Website

Founder Portfolio — Product Builder & Co-Founder Website

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4

Backend Engineer(3)

Sergei Serafimovich

From vision to product, without the chaos: https://aegte.dev

New to Contra

From vision to product, without the chaos: https://aegte.dev

Cover image for AI Assistant Backend Development for Comic Book App

AI Assistant Backend Development for Comic Book App

1

0

Cover image for Computer Vision Backend for Comic Book Cover Detection

Computer Vision Backend for Comic Book Cover Detection

1

1

Cover image for Christmas Sweater Image Editor Development

Christmas Sweater Image Editor Development

1

1

Cover image for OctoSale

1

1

Backend Engineer(2)

Wiktor Witkowski

Software Engineer - Api, Automation, Scripts

Software Engineer - Api, Automation, Scripts

Cover image for Microservices Architecture System

Microservices Architecture System

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5

Cover image for Leasing Platform

Leasing Platform

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4

Cover image for Excel Automation

Excel Automation

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5

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Backend Engineer(2)

pro

AI & Web3 dev: bots, scrapers, automations, apps, crypto

17: Followers

AI & Web3 dev: bots, scrapers, automations, apps, crypto

Cover image for 😍 Created payments flow +

😍 Created payments flow + admin dashboard for a mobile app: login, checkout, recurring subscription, invoices, and payment history. I used Stripe for payments (Checkout + Subscriptions) and Prisma for the database layer. Implemented webhook handling for subscription status updates, invoice history, and access control. Also built an admin dashboard to manage users, plans, and transactions.

27

469

Cover image for 🚀 Content Marketing - My

🚀 Content Marketing - My Real Cases Over the past 5+ years I’ve been building and scaling crypto-focused content ecosystems, combining short-form video, Telegram growth, and performance-driven funnels. Here are some real numbers behind my work: • Built a crypto Telegram community to 25K+ subs, monetized via ads & partnerships • Reached 100K+ total followers across all social platforms • Created and published 10000+ content posts • Generated $200K+ total revenue through crypto content, traffic funnels, and marketing collaborations • Produced high-volume short-form content (TikTok / YouTube Shorts / Reels) • Created and launched my own crypto products and tools • Work with 100+ influencers • Built a full growth funnel & “content factory” - strategy, converting views into subscribers and revenue.

3

538

Cover image for 🙌 Some of my Telegram chatbot development projects 1. PARSE...

🙌 Some of my Telegram chatbot development projects 1. PARSER + AI WRITER 2. TIKTOK Viral Scanner 3. YOUTUBE VIDEO TRANSLATOR 4. CRYPTO HEDGER 5. REPOST TT TO SHORTS And 20+ others

3

241

Cover image for 👍 MVP mobile app for learning English for beginners Tech st...

👍 MVP mobile app for learning English for beginners Tech stack: Flutter (Dart) - iOS & Android - Audio-based quizzes/UI-UX.

2

3

283

Backend Engineer(1)

Frontend-Driven AI Full Stack | AI Automation & Headless CMS

New to Contra

Frontend-Driven AI Full Stack | AI Automation & Headless CMS

Cover image for Softr: Internal admin systems

Softr: Internal admin systems

0

63

Cover image for Secure Crypto Brokerage Platform Development

Secure Crypto Brokerage Platform Development

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2

Cover image for Luaka Bop Digital Music Platform

Luaka Bop Digital Music Platform

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1

Cover image for VannaAI Text-to-SQL over private databases

VannaAI Text-to-SQL over private databases

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60

Backend Engineer(1)