Senior Software Engineer, Networking

Responsibilities

• Design, implement, and own core components of Ditto's networking and transport stack, spanning overlay networking (routing, virtual connections, channel lifecycle) and underlying physical transports and protocols (BLE, LAN, Wi-Fi Aware, AWDL, etc.).
• Drive the re-architecture of the networking stack toward a more modular, scalable, and high-performance design, establishing clear interfaces and ownership boundaries between transport layers and mesh abstractions.
• Debug and systematically improve real-world connectivity issues including data transfer reliability, MTU negotiation, pairing instability, throughput ceilings, and cross-platform data sync behavior.
• Build and optimize transport mechanisms with explicit attention to flow control, backpressure, congestion handling, retries, connection lifecycle management, and failure recovery.
• Identify and eliminate performance bottlenecks across latency, memory footprint, CPU utilization, and tail behavior in highly concurrent, asynchronous systems.
• Design protocol state machines, wire formats, and transport abstractions that remain correct under unreliable networks, intermittent connectivity, and constrained environments.
• Establish meaningful observability through targeted logging, metrics, and diagnostics to enable rapid production debugging and root-cause analysis.

Requirements

• 5+ years of professional experience building systems software, with at least 3 years focused on networking, transport protocols, or routing.
• Strong proficiency in Rust or C++, including ownership and borrowing semantics, async runtimes, concurrency primitives, and profiling/optimization techniques.
• Understanding of key mesh networking topics such as TCP, UDP, and QUIC semantics and tradeoffs, including connection establishment, congestion and flow control, retransmission behavior, MTU/fragmentation, and practical implications for latency, throughput, and reliability.
• Exposure to or experience working with networked services and protocols. Demonstrated ability to debug complex behavior in networked and concurrent systems (race conditions, deadlocks, resource leaks, latency spikes).
• Experience designing modular APIs and abstractions that scale across multiple implementations and evolve safely over time.
• Clear written and verbal communication skills in a distributed, asynchronous team environment.
• Passion to learn new networking technologies, APIs, and approaches to build at the bleeding edge of mesh networking.

Nice to Haves

• Experience with mesh networking protocols, routing algorithms, or gossip protocols.
• Understanding of mobile platform constraints including background execution models, battery optimization, OS suspension/resume cycles, and their impact on persistent connections.
• Experience with Apple Core Bluetooth or Android WiFi Aware APIs.
• Experience with Linux networking, sockets, async I/O, or low-level systems programming.
• Willingness to travel once per quarter for in-person team gatherings.