Building Loftia’s MMO Architecture with Epic Online Services and Hathora

Image courtesy of Qloud Games
August 21, 2025
This guest blog post was written by Justin Chu, Senior Software Engineer at Hathora, with interview quotes from Eric Mallon (Qloud Games’ Co-founder and CTO).

Hathora is a server orchestration platform, used by Qloud Games for their cozy, solarpunk MMO, Loftia. The game was wildly successful on Kickstarter and has amassed a community of over 400,000 passionate fans along the way.
Courtesy of Qloud Games
Don’t be fooled by their game’s cute graphics: the studio’s vision for Loftia’s multiplayer features were very ambitious from the start - particularly for a debut title. Those goals include solo-play alongside seamless online co-op, dynamic sessions that allow players to combine their houses, and large-scale social hubs shared across hundreds of players.
 
Our team recently caught up with Eric Mallon, the co-founder and CTO of Qloud Games, and he gave some insight into the key choices and challenges they faced while building out their game’s architecture. Keep reading to learn how Qloud Games used Epic Online Services (EOS) and Hathora to give their small team the power to execute a big vision.
Courtesy of Qloud Games

Inside Loftia’s early architecture

To achieve their ambitious goals with a small indie team, Qloud leaned on third-party tools rather than building tools themselves. As Eric explains, choosing a game engine was an easy call.

“Unreal Engine 5 was so easy to work with, with so much development pushed into it,” he says. “There really wasn’t another choice for us. [UE5] is easy to hire for, has tons of plugins, and has cross-platform support.”

Beyond the game engine, Eric was quick to explore the essential online services that would make their cozy MMO possible. Nearly one and a half years prior to their first alpha playtest, Qloud was already using both Epic Online Services and Hathora to enable their team’s remote playtests.

“Epic Online Services and Hathora were both easy to get started with,” says Eric. “What’s even better is that both have been flexible to build upon as well.”
Courtesy of Qloud Games

The right tools for a lean team

“We were always confident in our team’s engineering talent and abilities to build our own backend system,” he says. “But being a small team, I knew we would want to use existing tools to handle time-intensive tasks like cross-platform player authentication and scalable server hosting.”

Cross-platform player authentication was a feature Eric knew would take a lot of developer time to implement well, and Epic Online Services had a polished, free solution that made it easy to start with. Over time, Qloud has continued to take advantage of even more of Epic Online Services’ modular features, such as session management and voice chat.

As for server hosting, Eric and his team had the experience to understand just how much work it takes to build and maintain such a system—which often requires a separate team dedicated to maintaining and monitoring it in real time—and that this was not something Qloud had the luxury of doing for Loftia.

“Hathora was really quick to set up and it’s specifically built for gaming,” says Eric. “It’s great that we don’t have to directly manage EC2 instances, because we have a million other things that we need to be focusing on.”
Courtesy of Qloud Games

Sustainable scalability is vital

Using Epic Online Services’ free solutions was a no-brainer for the Qloud CTO and his team, and with hundreds of games launching with EOS, serving almost a billion players worldwide, Eric felt confident in the services’ ability to scale sustainably. “Early ramp-up costs are just as important as the end-scale costs, especially for indie teams like us,” says Eric.

Game servers, on the other hand, are notoriously one of the most expensive costs of running a multiplayer game. Hathora’s usage-based pricing was immediately attractive to Eric. That, plus Hathora’s ability to offer low-cost bare metal servers seamlessly with cloud burst, gave Eric the confidence that their server costs would be sustainable during early development, testing, and for launch.

Loftia servers have been steadily running on Hathora for nearly two years, from early internal testing all the way to Loftia’s most recent alpha playtest with over 10,000 early backers. Throughout, Epic Online Services has provided the architecture’s backbone, enabling users to seamlessly connect, match, and play across platforms.

“It’s comforting for me to know that both Epic Online Services and Hathora will enable Loftia’s costs to scale favorably at launch and beyond,” says Eric

Loftia’s matchmaking architecture: Epic Online Services x Hathora integration overview

Loftia’s backend architecture can be organized into two core groups:
  1. Data and telemetry pipelines: handling persistence, analytics, and long-term player state. For this, Qloud uses tools like Sentry, AWS Firehose, and DynamoDB.
  2. Real-time gameplay infrastructure: responsible for running sessions where players interact live.

What makes Loftia especially interesting is how Qloud have tackled matchmaking - not in the traditional competitive sense, but in how players are smoothly dropped into the right session to start playing with friends immediately. The approach is both elegant and surprisingly simple.

The world types

Loftia supports two distinct types of worlds that shape their matchmaking needs:
  1. Social Hubs – Up to 100 players per session. These are shared public spaces where players can meet, complete quests, forage, and interact with NPCs.
  2. Player Houses – Up to 25 players. These are public zones where players get dynamically assigned a housing ‘slot’ for a session, sharing their home in a small neighborhood with up to eight players and friends. 
Courtesy of Qloud Games

How players join worlds

The player connection flow is designed for speed and reliability:

1. A player requests to join a world
2. The game uses Epic Online Services to search for an existing session: 3. If no match is found, a new server is spun up via Hathora.
  • Once online, that server registers itself with Epic Online Services so players can connect. Integration tip: Epic Online Services Sessions map well with Hathora Rooms

At a high level this flow seems simple, but as with any MMO, the edge cases are where the cracks show up. Let’s dive into a few interesting challenges Qloud hit:
 

Challenge #1: The new server race condition

Early on, Loftia’s team encountered a tricky challenge: how to avoid over-provisioning servers when no sessions match.

Their goal was to consolidate players into as few Social Hub sessions as possible—both for technical efficiency and to keep worlds feeling alive. This same principle applied to Player Houses, too.

Their solution? Use an AWS Lambda buffer that queues server requests while a new instance spins up in Hathora. This buffer avoids redundant server launches when multiple join requests hit simultaneously.

Battle tested: During Loftia’s first private alpha, lacking this buffer logic caused a big burst of extra servers to spin up. Yet another reminder why alpha testing is so crucial!
 

Challenge #2: Reserving server slots

Another subtle but critical detail: reserving open slots during the join process. If five players attempt to join a server with only five open spots, there’s a risk of all five requests overlapping and one or more players getting rejected.

Loftia sidesteps this issue by using Unreal Online Beacons not just for querying availability - but also to reserve a spot in the session before the connection attempt begins. It’s a small detail, but one that dramatically improves the moment-to-moment experience.

In cozy, social-first games like Loftia, even brief friction can disrupt the magic, and addressing these small implementation details can have a meaningful impact on the player experience.

Cozy roots for a scalable launch

Building an MMO as an indie studio is certainly still an ambitious quest to pursue, especially for a first title. But having a thoughtful approach to your game’s design and architecture, and with Epic Online Services and Hathora to help make that architecture a reality, you can absolutely lower the barrier to entry for games like Loftia.
 
Eric and the Qloud team are paving the way for small teams to build big MMO experiences by leveraging the right tools for their team. And much like Loftia’s solarpunk theme, the future looks bright for this small team aiming to soar high.
 

Links and further reading

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