Node.js / TypeScript Dev for Browser Based MMO Game Backend

I’m developing an MMORPG RTS, a browser based multiplayer strategy game.

The project is already in development and has an existing Node.js / TypeScript codebase and game engine.

I’m looking for an experienced developer to help continue the backend development.

The game runs in a shared universe where players manage buildings and units, research technology, move fleets, fight other players and compete for territory. Actions continue to resolve while players are offline.

A core requirement of the game is deterministic, server authoritative simulation. Combat, movement, resource production and other game systems need to produce consistent results from the same inputs.

The existing engine is structured as pure TypeScript and is shared between server side systems and the combat simulator.

The game specification is already extensive. It defines fleet movement, resource production, construction and research queues, combat, colonisation, espionage, player protection, territory, sensors and other systems. For example, fleet travel uses deterministic coordinates, ship speeds and technology modifiers, with the slowest ship determining fleet speed.

The work will involve:
- Working with the existing Node.js / TypeScript codebase
- Extending and completing backend game systems
- Implementing mechanics from an existing specification
- Maintaining deterministic game engine behaviour
- Working with persistent timed events, queues and fleet movements
- Integrating game-engine logic with the API/database where required
- Fixing bugs and inconsistencies in existing systems
- Writing or maintaining automated tests for important game rules
- Helping prepare the backend for multiplayer testing and eventual production use

This is not primarily a graphics/game engine role. The game is browser based and interface driven. I am specifically looking for someone strong in backend application architecture and TypeScript/Node.js.

Required experience:
- Strong Node.js and TypeScript
- Backend/API development
- Relational databases and data modelling
- Automated testing
- Git
- Ability to understand and work safely within an existing codebase
- Experience implementing business/game rules from written specifications
Experience with persistent multiplayer games, simulation systems, background workers/queues or server-authoritative game logic would be useful, but is not essential if your backend fundamentals are strong.

When applying, please answer these three questions:
1. Tell me about the most technically relevant Node.js/TypeScript project you have personally worked on. What parts did you implement?
2. How would you approach testing a deterministic game engine where identical inputs must always produce identical outputs?
3. Have you worked with systems involving scheduled/background processing, queues, timed events or persistent multiplayer state? If so, briefly explain.

Please don't send a generic agency introduction. I'm interested in the developer who would actually be working on the project.