About CardNexus

CardNexus is building the ultimate platform for the Trading Card Game (TCG) community. Designed for players, collectors, investors, and game stores, we simplify collection management, provide real-time market insights, and streamline trading through smart matching technology. Our all-in-one solution bridges the gaps between fragmented tools and outdated systems, enabling users to value, trade, and grow their collections efficiently.
Founded in 2024 by a team of repeat entrepreneurs and lifelong TCG enthusiasts, CardNexus brings together deep expertise in technology, product design, and competitive trading card games. We’re on a mission to redefine how millions of TCG fans engage with their collections—from streamlining inventory to optimizing trades and building a thriving community.
If you’re passionate about TCGs and want to shape the future of the industry, we’d love to have you on board!

Role overview

We are hiring a Freelance backend engineer to join us immediately to tackle our most important projects, including but not limited to :

• Inventory management
• Import and export systems
• Deployment and industrialization (Logging, monitoring, observability, scalability)
• Perforrmance (API, Mongo database, etc.)

You will work with our CPO, CTO, and two founding engineers.

What You’ll Do

As a Senior Backend Engineer, you will take full ownership of backend architecture, from problem definition to implementation and optimization. You will be responsible for delivering high-performance, scalable solutions for a high-traffic marketplace, ensuring every feature is built with efficiency, resilience, and maintainability in mind. Over the next 24 months, you will:

• Deliver Complex Features: Lead the implementation of intricate features such as:
  • Real-time card scanning, inventory management, and trade matching.
  • A scalable inventory system capable of handling large user collections efficiently.
  • Integration of a Payment Service Provider (PSP) and user wallet system, ensuring secure transactions and seamless payment processing.
  • Performance and cost optimization at all levels, ensuring minimal resource usage while maintaining high speed.
  • Infrastructure scaling strategies to handle millions of daily requests reliably.
• Optimize for Performance and Cost Efficiency: Ensure that every piece of infrastructure and code is optimized for speed, resource efficiency, and minimal operational cost.
• Scale Infrastructure for High Traffic: Build robust logging, monitoring, and scaling strategies to handle millions of daily requests seamlessly.
• Ensure Security and Compliance: Implement rigorous security measures, including KYC processes, to protect users and maintain trust.
• Streamline CI/CD and DevOps: Enhance deployment pipelines for seamless integration and rapid iteration.
• Solve Broad and Deep Technical Challenges: Leverage your expertise across databases, cloud infrastructure, and backend technologies to deliver cutting-edge solutions.

What You Bring

• Proven Track Record of Ownership: You take full accountability for projects, seeing them through from conception to delivery, ensuring high-quality results.
• Expertise in High-Traffic Systems: Experience designing and optimizing backends for large-scale, high-volume platforms with demanding performance requirements.
• Deep Database Mastery: Extensive hands-on experience with MongoDB, relational databases, and NoSQL solutions, with a strong ability to optimize queries and data structures for performance and scalability.
• Strong Backend Development Skills: Advanced proficiency in Node.js, TypeScript, and backend architecture.
• Broad Technical Knowledge: Comfort with cloud infrastructure (AWS, GCP), logging, monitoring, caching, and DevOps best practices.
• Efficiency-Driven Mindset: Ability to write clean, optimized code that minimizes execution time and resource consumption.
• Problem-Solving Excellence: Ability to decompose complex challenges into scalable, maintainable solutions with a performance-first approach.
• Fluent Communication: Strong written and spoken English skills, capable of articulating ideas clearly in a collaborative, fast-paced environment.

Bonus Points:

• Experience working on a large-scale marketplace with high traffic.
• Expertise in MongoDB optimization and sharding strategies.
• Experience with frontend technologies like React, Next.js.
• Passion for Trading Card Games (TCGs) or gaming culture.

What We Offer

• Fully Remote Work: Enjoy the freedom to work from anywhere with flexible hours that fit your lifestyle.
• Competitive Compensation: We offer a competitive salary that reflects your skills, expertise, and contributions.
• Professional Growth: Collaborate with a passionate team of TCG enthusiasts and tech experts to tackle cutting-edge challenges.
• Innovative Culture: Join a gamer-centric environment that celebrates creativity, gaming, and technology.
• Impactful Work: Play a key role in transforming the $15B TCG market with tools that truly make a difference for the community.