Freelance Backend Engineers in Masovian Voivodeship

Freelance Backend Engineers in Masovian VoivodeshipFreelance Backend Engineers in Masovian Voivodeship

Projects People

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

1

Cover image for Computer Vision Backend for Comic Book Cover Detection

Computer Vision Backend for Comic Book Cover Detection

1

2

Cover image for Christmas Sweater Image Editor Development

Christmas Sweater Image Editor Development

1

2

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

0

5

Cover image for Leasing Platform

Leasing Platform

0

4

Cover image for Excel Automation

Excel Automation

0

7

Placeholder project card media

View more →

Backend Engineer(2)

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

21: 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

477

Cover image for 🚀 I recently built a

🚀 I recently built a custom AI automation system with 50+ AI agents designed to run business workflows automatically. The system includes specialized agents such as: • CEO agent (task coordination) • LinkedIn lead generation agent • Telegram lead finder • Email scraping & outreach agent • Job monitoring agent • AI response assistant • Data analysis agents All agents communicate through a centralized hub and can work 24/7 without manual supervision. The system handles tasks like: lead generation data scraping automated outreach monitoring opportunities workflow automation Tech stack used: Python • OpenAI / Claude • Automation agents • Web scraping • API integrations If you're looking to build custom AI agents for your business workflows, feel free to reach out.

1

47

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

582

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

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

133

Cover image for Paramark SaaS Marketing Analytics Platform Redesign

Paramark SaaS Marketing Analytics Platform Redesign

1

3

Cover image for Travala Online Booking Platform Redesign and Optimization

Travala Online Booking Platform Redesign and Optimization

1

3

Cover image for Cross-Platform AI SaaS Enhancement for Sintra

Cross-Platform AI SaaS Enhancement for Sintra

1

2

Backend Engineer(1)