Freelancer logo
Log In Sign Up
Post a Project

EXPLORE

Backend Development Frontend Development Mobile App Development Node.js Web Development
Profile cover photo
User Avatar

Jaroslav C.

@jaroslavcaprata

monthly-level-four.svg
5.0
7

4.3

4.3

100%

🚀 Senior Full Stack Engineer 🚀

$30 USD / Hour

・

Flag of

Czech Republic (7:07 PM)

・

Joined on October 8, 2025

・

1 Recommendation

$30 USD / Hour

・

I’m a Scalable AI & Mobile App Engineer focused on building intelligent applications, automation systems, and modern digital products that solve real business problems. I specialize in developing AI-powered SaaS platforms, mobile applications, and full-stack systems that are designed for scalability, performance, and long-term growth. My work goes beyond simple prototypes — I build production-ready solutions with clean architecture, maintainable code, and seamless user experiences across web and mobile platforms. My expertise includes: • AI-powered applications • Mobile app development (iOS & Android) • LLM/GPT integrations • Workflow & business automation • Full-stack web development • API architecture & integrations • Scalable backend systems • Performance-focused engineering I combine strong software engineering principles with modern AI technologies to create solutions that are reliable, efficient, and user-focused. Whether you need an AI-powered mobile app, intelligent automation, or a scalable SaaS platform from scratch, I focus on delivering systems that are practical, elegant, and built for real-world use.

Verifications

On time

100%

On budget

100%

Accept rate

92%

Repeat hire rate

10%

Freelancer Mobile App Developers Czech Republic
See all Mobile App Developers in Czech Republic

Portfolio

Portfolio

13897668
I’ve sketched out an original video-game concept that stands or falls on smart, well-integrated artificial-intelligence features. Right now I’m looking for a developer who can help me turn that idea into a playable prototype, starting with a tight vertical slice that proves the AI-driven mechanics work in real time. The headline requirements are simple: • Build an early, playable scene in the engine you feel is most suitable—Unity, Unreal or Godot all fit the brief. • Design and code at least one core AI system that directly shapes gameplay—think believable NPC behaviour, procedural level generation or dynamic difficulty that reacts to the player. We’ll decide together which element delivers the biggest “wow” factor first. • Supply clean, well-commented source files and a short read-me so I can keep the project moving after delivery. A clear, frequent communication style is essential; I’ll share concept art, flow-charts and reference builds the moment we connect so you can estimate t

AI Video Game Development

I’ve sketched out an original video-game concept that stands or falls on smart, well-integrated artificial-intelligence features. Right now I’m looking for a developer who can help me turn that idea into a playable prototype, starting with a tight vertical slice that proves the AI-driven mechanics work in real time. The headline requirements are simple: • Build an early, playable scene in the engine you feel is most suitable—Unity, Unreal or Godot all fit the brief. • Design and code at least one core AI system that directly shapes gameplay—think believable NPC behaviour, procedural level generation or dynamic difficulty that reacts to the player. We’ll decide together which element delivers the biggest “wow” factor first. • Supply clean, well-commented source files and a short read-me so I can keep the project moving after delivery. A clear, frequent communication style is essential; I’ll share concept art, flow-charts and reference builds the moment we connect so you can estimate t

AI Video Game Development

13897664
Please, this must be the first line of your bidd: DEVIWORKS DOLIBARR - ERP CUSTOMIZATION In Dolibarr, I need to: Copy the BOM module and customize it so I can view nested BOMs in a tree view, including descriptions. Currently, the default module only shows the first nested level, but I want to see all of them. Copy the Manufacturing Orders module and add the ability to launch manufacturing orders for a BOM and all nested sub-BOMs in one step. Stocks: I need manufacturing orders and replenishment to pick up product stocks only from one warehouse. For example, if a product is in the “Quality Warehouse,” it cannot be consumed in an MO, and it must be proposed for purchase unless you move it to the “Main Warehouse.” Add product states (for example: Released, Under Modification, Obsolete, etc.). The product state must block manufacturing and purchasing orders. The modifications must be compatible with new releases of Dolibarr, if possible. You must also create clear documentation expla

Enlite Prime Resized

13847218
I have completed go live webRTC functionality. I have implemented live streaming option and reporter and editor portal and admin portal which can manage reporter and editor.

High-Quality Low-Latency Newsroom

I have completed go live webRTC functionality. I have implemented live streaming option and reporter and editor portal and admin portal which can manage reporter and editor.

High-Quality Low-Latency Newsroom

13838962
Phase 1 goal: A working retro 2D game generator with four templates and a clean engine API. Phase 2 goal: AI-assisted generation (art, levels, deeper gameplay variation). Please design the engine with that future expansion in mind.

Game development

13838953
I delivered quickly and stayed fully engaged throughout the work. I was flexible with changes and adapted to new requirements without delay. Communication was clear, prompt, and constructive. I took ownership of the integration tasks and moved them forward decisively. My implementation added useful functionality with minimal disruption to existing code. Overall, I was reliable and effective.

LLM Studio Integration

13804708
This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

13897668
I’ve sketched out an original video-game concept that stands or falls on smart, well-integrated artificial-intelligence features. Right now I’m looking for a developer who can help me turn that idea into a playable prototype, starting with a tight vertical slice that proves the AI-driven mechanics work in real time. The headline requirements are simple: • Build an early, playable scene in the engine you feel is most suitable—Unity, Unreal or Godot all fit the brief. • Design and code at least one core AI system that directly shapes gameplay—think believable NPC behaviour, procedural level generation or dynamic difficulty that reacts to the player. We’ll decide together which element delivers the biggest “wow” factor first. • Supply clean, well-commented source files and a short read-me so I can keep the project moving after delivery. A clear, frequent communication style is essential; I’ll share concept art, flow-charts and reference builds the moment we connect so you can estimate t

AI Video Game Development

I’ve sketched out an original video-game concept that stands or falls on smart, well-integrated artificial-intelligence features. Right now I’m looking for a developer who can help me turn that idea into a playable prototype, starting with a tight vertical slice that proves the AI-driven mechanics work in real time. The headline requirements are simple: • Build an early, playable scene in the engine you feel is most suitable—Unity, Unreal or Godot all fit the brief. • Design and code at least one core AI system that directly shapes gameplay—think believable NPC behaviour, procedural level generation or dynamic difficulty that reacts to the player. We’ll decide together which element delivers the biggest “wow” factor first. • Supply clean, well-commented source files and a short read-me so I can keep the project moving after delivery. A clear, frequent communication style is essential; I’ll share concept art, flow-charts and reference builds the moment we connect so you can estimate t

AI Video Game Development

13897664
Please, this must be the first line of your bidd: DEVIWORKS DOLIBARR - ERP CUSTOMIZATION In Dolibarr, I need to: Copy the BOM module and customize it so I can view nested BOMs in a tree view, including descriptions. Currently, the default module only shows the first nested level, but I want to see all of them. Copy the Manufacturing Orders module and add the ability to launch manufacturing orders for a BOM and all nested sub-BOMs in one step. Stocks: I need manufacturing orders and replenishment to pick up product stocks only from one warehouse. For example, if a product is in the “Quality Warehouse,” it cannot be consumed in an MO, and it must be proposed for purchase unless you move it to the “Main Warehouse.” Add product states (for example: Released, Under Modification, Obsolete, etc.). The product state must block manufacturing and purchasing orders. The modifications must be compatible with new releases of Dolibarr, if possible. You must also create clear documentation expla

Enlite Prime Resized

13847218
I have completed go live webRTC functionality. I have implemented live streaming option and reporter and editor portal and admin portal which can manage reporter and editor.

High-Quality Low-Latency Newsroom

I have completed go live webRTC functionality. I have implemented live streaming option and reporter and editor portal and admin portal which can manage reporter and editor.

High-Quality Low-Latency Newsroom

13838962
Phase 1 goal: A working retro 2D game generator with four templates and a clean engine API. Phase 2 goal: AI-assisted generation (art, levels, deeper gameplay variation). Please design the engine with that future expansion in mind.

Game development

13838953
I delivered quickly and stayed fully engaged throughout the work. I was flexible with changes and adapted to new requirements without delay. Communication was clear, prompt, and constructive. I took ownership of the integration tasks and moved them forward decisively. My implementation added useful functionality with minimal disruption to existing code. Overall, I was reliable and effective.

LLM Studio Integration

13804708
This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

This game is a continuous, running game that begins in the desert, then transitions through a sandstorm to a fantasy city, and then to the enchanting library. It realistically depicts real characters learning in a fantasy city. The game is designed for children ages 6 to 12, with colorful locations, obstacles, stars, and more to appeal to their innocence.

Polish & Optimize Web-Based 2D Endle

5.0 · 7 Reviews
7 Reviews
C
Flag of

Lewis S.

5.0

$72 USD

2 months ago

AI Video Game Development

Good guy I love his work great communication as well

Unreal Engine
Unity
AI Text-to-speech
AI Text-to-text
AI Model Development

+2 more

Share

User Avatar
Flag of

Pronoor S.

5.0

$10 USD

2 months ago

Node+ Vue+ $50

This Milestone was started in error. So we practically have no work experience with the freelancer. He seems to be a nice guy with willingness to earn business.

Node.js
PostgreSQL
Vue.js

Share

C
Flag of

Kabul S.

5.0

₹32,000 INR

3 months ago

High-Quality Low-Latency Newsroom Streaming

He worked very professionally, in time bound manner, very responsive - replies immediately with solution. Executed the project efficiently, has good knowledge in his field. Very proficient in streaming tools n technology. Highly recommended.

Python
Video Broadcasting
Node.js
Docker
Backend Development

+4 more

Share

User Avatar
Flag of

Timo B.

5.0

$120 USD

3 months ago

LlmConnector Development for Copilot and Codex - C# App (incl source available)

Jaroslav delivered quickly and stayed fully engaged throughout the work. He was flexible with changes and adapted to new requirements without delay. Communication was clear, prompt, and constructive. He took ownership of the integration tasks and moved them forward decisively. His implementation added useful functionality with minimal disruption to existing code. Overall, he was reliable and effective, and I would gladly work with him again.

.NET
C# Programming
Software Architecture
WPF
JSON

+3 more

Share

C
Flag of

Lewis S.

5.0

$42 USD

3 months ago

Custom Software Development Partner

I love working with jaro he's incredible the best!

Project Management
Mobile App Development
Agile Development
Software Development
Web Development

+3 more

Share

Experience

Full Stack Web, Mobile & AI Engineer

Nov, 2022 - Dec, 2025

•

3 years, 1 month

Freelance / Product Development

Nov, 2022 - Dec, 2025

•

3 years, 1 month

Built intelligent web and mobile applications as a Full Stack and AI Engineer. Integrated AI features such as NLP, chatbots, recommendation systems, and predictive analytics into production products. Developed modern frontends with React and Next.js, scalable backends with Node.js and NestJS, and deployed reliable, cloud-ready systems.

Flag of

Kladno, Czech Republic

Nov, 2022 - Dec, 2025

•

3 years, 1 month

Senior Full Stack & Mobile App Engineer

Sep, 2020 - Oct, 2022

•

2 years, 1 month

Freelance / Consulting

Sep, 2020 - Oct, 2022

•

2 years, 1 month

Led development of scalable web and mobile applications as a Senior Full Stack Engineer. Built backend systems using NestJS, Express, and Spring Boot, and developed cross-platform mobile apps with React Native and Flutter. Implemented authentication, payments, real-time features, and push notifications while improving performance, security, and scalability in production environments.

Flag of

Kladno, Czech Republic

Sep, 2020 - Oct, 2022

•

2 years, 1 month

Full Stack Web Engineer

Jan, 2019 - Aug, 2020

•

1 year, 7 months

Freelance / Independent

Jan, 2019 - Aug, 2020

•

1 year, 7 months

Worked as a Full Stack Web Engineer delivering end-to-end web applications for startups and small businesses. Built responsive frontend interfaces using React, Vue.js, and Angular, and developed secure backend services with Node.js, Laravel, and Django. Designed and optimized PostgreSQL, MySQL, and MongoDB databases, integrated third-party APIs, and focused on clean architecture, performance, and maintainability.

Flag of

Kladno, Czech Republic

Jan, 2019 - Aug, 2020

•

1 year, 7 months

Education

Czech Technical University in Prague

2015 - 2018

•

3 years

Master in Information Technology

Flag of

Czech Republic

2015 - 2018

•

3 years

Certifications

P

Preferred Freelancer Program SLA

Freelancer logo US (International) / English
Help & Support

Freelancer

Categories Projects Contests Freelancers Enterprise Innovation Challenges AI Development Membership Preferred Freelancer Program Project Management Local Jobs Photo Anywhere Showcase API for Developers Get Verified

About

About us How it Works Security Investor Sitemap Stories News Team Awards Press Releases Careers

Terms

Privacy Policy Terms and Conditions Copyright Policy Code of Conduct Fees and Charges

Partners

Escrow.com Loadshift Warrior Forum

Apps

Apple App Store logoGoogle Play logo

Registered Users

Total Jobs Posted

Freelancer ® is a registered Trademark of Freelancer Technology Pty Limited (ACN 142 189 759)

Copyright © 2026 Freelancer Technology Pty Limited (ACN 142 189 759)