Freelance Gameplay Programmer with 8+ Years of Experience Modding Valve's Games

Collaboration & Jobs
1

Hi,

My name is Justin, and I’m a professional game developer with over 8 years of experience. Based in Germany, I specialize in gameplay engineering, particularly AI systems. As a self-taught developer, I’ve acquired my skills through hands-on projects and continuous learning, which has allowed me to tackle a wide range of complex problems in game development.

I pride myself on being detail-oriented and thoroughly communicative, often asking questions to ensure the end result aligns perfectly with my clients’ expectations. This approach has consistently earned me positive feedback and repeat business.

In the past, I’ve worked on mods for popular Valve games like CS: GO, Left 4 Dead 2, and Team Fortress 2. One of my most recent projects was developing a highly performant NextBot (AI) system from scratch for a Zombie Survival game mode in Garry’s Mod. If you’re interested in reviewing the code to better understand my engineering approach, feel free to send me a DM, and I’ll be happy to share it privately.

My strengths include:

  • Gameplay engineering with a focus on AI and complex systems.
  • Solid understanding of modern game engines like Unreal Engine and Unity, as well as experience with in-house engines.
  • Proficiency in C/C++, scripting languages (Lua, Pawn, Squirrel), and visual scripting (Unreal Blueprints).

Specialized skills I have:

  • Memory hacking, including understanding of class structures, virtual tables, and binary file manipulation.
  • Techniques for manipulating and analyzing game memory to achieve specific outcomes or modify behavior.
  • Concepts such as detours and virtual table hooking.

You can explore my work further by visiting my portfolio:

If you’re looking for a reliable and adaptable developer who can contribute to your projects, I’d be happy to discuss how we could work together. Whether you need AI development, gameplay mechanics, or codebase integration, I’m confident I can help you out.

For feedback from previous clients, feel free to check out my Fiverr profile. Most of my projects there have focused on game mod development, and you can find verified reviews showcasing my work and client satisfaction.

I operate as an independent contractor (sole proprietor), and my rates reflect the quality of service, expertise, and the associated costs of delivering professional work, including taxes and operational expenses. While I typically work on a per-project basis, I can also offer day rates depending on the project’s scope.

My process is as follows:

  • I charge a daily rate during which we’ll discuss your project and its details. A comprehensive document outlining everything is preferred but not mandatory; however, for both our protection, everything must be in writing to avoid misunderstandings or disputes. This is non-negotiable. If the project scope is unclear, we can clarify it during this time.
  • Once the scope is defined, I’ll provide an estimate of the timeline and cost for implementation. Payment terms can be discussed and agreed upon based on the project’s scope and requirements. For larger projects with multiple milestones, payment for each milestone is required upfront before work on that milestone begins.
  • Throughout the project, I’ll keep you updated at every milestone, allowing us to discuss feedback, potential adjustments, and any changes. Please note that changes outside the initial agreement will incur additional costs.
  • Upon completion, I offer a warranty period during which any issues caused by my work will be fixed free of charge.

Next steps:
If you’d like to review my resume for more detailed information about my skill set, I’m happy to share it privately as well.

Availability: I’m usually available to start new projects right away or within a few days, depending on my current commitments.

While my portfolio highlights some of my key projects, my experience extends well beyond these examples. I’m open to discussing other aspects of game development, including areas not covered in my showcased work.

If you’re interested in working together or have any questions, don’t hesitate to reach out via email or connect with me on Discord at justin_chellah.

Have a great day!