Important Details

• Level: Senior
• Type: Contract / Freelance (with potential long-term collaboration)
• Engine: Unreal Engine 5.7.3
• Project: Co-op Horror Puzzle Adventure (PC)
• Mode: Fully Remote (One, one and a half month) as consultant possible

This is a short-term project, and we fully support candidates who wish to combine it with an existing job. We value reliability, communication, and

high-quality craftsmanship.

We are looking for an experienced Unreal Engine Multiplayer Developer with strong knowledge of multiplayer gameplay architecture, replication, networking, and scalable system design.

Our project build with Unreal Engine 5.7 co-op with Steam lobbies + Steam invites already working (implemented via Advanced Sessions Plugin and a custom GameInstance flow). Core gameplay works in multiplayer for basic features, but upcoming mechanics were built locally first and must be converted into server-authoritative replicated gameplay.

We need an engineer who can own networked gameplay architecture and ship the next set of multiplayer features with solid replication, join-in-progress support, and stable physics handling.

Responsibilities

• Develop and maintain multiplayer gameplay systems using Unreal Engine 5.6 (C++ only, NO Blueprints)
• Implement and optimize replication logic, RPCs, networked character interactions.
• Design clean multiplayer architecture, including player states, game states, sessions (Steam Lobby would be plus), lobbies, and matchmaking logic.
• Ensure stable synchronization between clients in complex co-op scenarios (puzzles, physics interactions, character abilities).
• Profile and troubleshoot network issues (latency, desync, packet loss, server load).
• Optimize performance for both server and client (bandwidth, CPU, memory).
• Help define best practices for multiplayer code structure and workflow.

Current Stack / Baseline

• Steam lobbies + invites + join flow already integrated
• Advanced Sessions Plugin (sessions/lobbies)
• Current “carry/pickup” system uses client-driven movement with periodic unreliable Server RPC transform updates (timer-based). We see occasional jitter/feedback issues.

Our multiplayer foundation already exists:

• Steam lobbies, invites, and session joining are implemented (Advanced Sessions Plugin).
• Project currently uses a Listen Server model (one player hosts) — no dedicated servers.
• Core gameplay runs in multiplayer for baseline interactions.

We are now entering the critical phase of converting locally implemented gameplay systems into fully server-authoritative multiplayer gameplay.

Current Architecture

• Steam P2P Listen Server
• Host player acts as authoritative server.
• No dedicated server planned during this stage (but code should remain compatible if we add one later).
• Advanced Sessions Plugin handles lobby/session flow.
• Many mechanics were prototyped locally and must now be replicated properly.
• Existing carry system uses client-driven movement + periodic RPC transform updates (causing jitter under latency).