Running Complex Game Configs at Scale: What You’ll Wish You Knew Earlier

This is a recap of a longer email Antti sent out directly to Metaplay Tech Talks subscribers. To get the full version direct to your inbox, with new insights every month, sign up to Metaplay Tech Talks here.

When Antti first started out in game development, game configuration wasn’t exactly top of mind. “If you’d have told me how critical a robust and scalable game config system would be,” he says, “I probably would have nodded along politely and then gotten back to fixing the next-most-immediate problem.”

That mindset is common—and understandable. At first glance, configs seem simple: a few numbers in code, maybe a spreadsheet or JSON file if someone wants more flexibility. But Antti learned the hard way that as soon as your game starts scaling, those quick fixes become your biggest bottlenecks.

Build with Configs in Mind from Day One

One of the most common mistakes teams make is treating configs like an afterthought. “You start by hardcoding a few values into your C# classes. Then a designer comes along and wants to tweak something, so you hack together a JSON file. Before you know it, your codebase and your content are tangled together like spaghetti.”

The better approach is to design for configurability from the beginning. That means thinking early about what parts of the gameplay will need to change over time, what designers should be able to control without needing a programmer, and where you want flexibility versus rigidity.

“If you set up the right building blocks early,” Antti says, “you’ll save yourself—and your entire design team—months of pain later.” It’s not just about avoiding future refactors. It’s about speed, clarity, and collaboration. “Programmers lay the foundation,” he says. “Designers build the house.”

Almost Anything Can (and Should) Be Configurable

Once you’ve built the foundations, the real power of config-driven development starts to emerge.

“When you get configs right,” Antti says, “you unlock an incredible superpower: almost anything in your game can be made configurable remotely.”

And he means anything. Metaplay has worked with studios where entire gameplay systems are data-driven, letting teams iterate without ever touching code or pushing a new client build. Teams have configured entire game levels remotely—board layouts, merge chains, character stats, full progression systems—all without writing a single line of code.

This flexibility isn’t just a win for designers. It’s a huge boost for LiveOps. Want to A/B test different item prices? Adjust the level progression on the fly? Roll out a limited-time event with new rewards? Easy—if you’ve built the right pipelines.

To support this, Metaplay encourages teams to define flexible templates in code early on, use dynamic asset loading systems like Unity’s Addressables to decouple logic from assets, and validate every config before publishing. “Never let a bad row take your whole live game down.”

Antti points to merge games as an area where this shines brightest. “The most impressive implementations I’ve seen are in merge games where the entire progression and gameplay logic is modeled in configs. Clean, powerful, and incredibly fast to iterate on. When you nail this, your code becomes elegant—and your designers become unstoppable.”

Where Things Get Messy: Managing Configs at Scale

Configuring gameplay is one thing. Managing configs at scale? That’s where the real headaches begin.

“If you start with one Google Sheet shared between three people, it feels fine,” Antti explains. “But when you have 200 people all editing different parts of your game’s economy, level design, and item stats? Chaos.”

Metaplay has seen the usual pain points firsthand: overwritten changes, no version control, and manual merge conflicts across data sources.

To avoid this, Metaplay built its system to source configs from multiple formats—spreadsheets, CSVs, Git-tracked files—and compile them into a single, validated config bundle.

A key part of their solution is assigning clear domain ownership. For example, monetization teams manage economy configs, designers handle progression configs, and the core gameplay logic remains with the dev team. Each group works independently, but the build system stitches everything together into a single source of truth.

“The sooner you move away from ‘one big sheet’ thinking,” Antti says, “the smoother your scaling journey will be.”

The Gotcha No One Warns You About: File Size

One lesson Antti wishes more teams knew in advance? Config size matters. A lot.

“Configs start small—a few rows, a few KBs. But fast forward two years and suddenly you’re shipping 10MB+ JSON files to your players every update,” he says. “Even if you compress it, your mobile client still has to spend 30 seconds parsing it on startup. Not exactly a great player experience.”

That’s why Metaplay doesn’t rely on plain JSON. Their config system binary serializes all data, compresses it efficiently, and optimizes the deserialization path for low memory usage and fast loading.

The result? Massive config data—entire libraries of characters, levels, and meta-progression—loads quickly, even on low-end devices.

It’s one of those problems that doesn’t feel urgent until it suddenly is. “So if you’re building your own system,” Antti advises, “take it from me: optimize now, thank yourself later.”

Final Thoughts: Build for Tomorrow’s Unknowns

Looking back, Antti’s biggest advice is simple: don’t just build for today.

“It’s easy to think a quick-and-dirty config system will ‘do for now,’” he says. “But scaling a live game is unforgiving. Every early shortcut eventually becomes a headache. Every unplanned growth moment becomes a scramble.”

At Metaplay, the difference a robust config system makes is undeniable: faster iteration, safer updates, happier teams—and, ultimately, a better experience for players.

“If you’re starting your journey now,” Antti says, “I hope you’ll take these lessons to heart—and avoid learning them the hard way.”

And if you're already encountering scaling challenges? You're not alone. “We’ve been there too,” he adds. “Let me know if you'd like to talk through it—I’d love to chat.”

Got thoughts or questions? The Metaplay team would love to hear from you. Reach out with your feedback or suggest a topic for a future Tech Talk.