Ditto · 2 weeks ago
Senior Software Engineer, SDK
United States
Full-time
Remote
Senior Level
$223K/yr - $305K/yr
5+ years expDitto is a fast-growing startup redefining how data moves at the edge, seeking a Senior Software Engineer to lead the technical direction of their JavaScript SDK. The role involves architecting the WebAssembly layer, designing APIs, and solving complex systems problems to enable developers to build real-time, offline-capable applications.
CollaborationProduct DesignSoftwareUX Design
Responsibilities
Design and maintain FFI boundaries: Own the interface between Ditto's Rust core and JavaScript, using wasm-bindgen, and cross-platform binding generators like UniFFI. Design thread-safe FFI boundaries that prevent data races across language runtimes
Solve cross-runtime concurrency challenges: Make Rust's async ecosystem work within browser constraints, including Web Workers, SharedArrayBuffer, Atomics, and the Rust-to-JS callback story. Bridge Rust's async runtime (tokio) with JavaScript's event loop and Web Workers
Own the WASM compilation pipeline: Design and maintain the build toolchain that compiles Ditto's Rust core to WebAssembly, optimizing for size, memory usage, performance, and browser compatibility
Architect JavaScript/TypeScript APIs: Create idiomatic, type-safe APIs that feel native to JavaScript developers while efficiently bridging to the underlying WASM module
Own quality from test to release: Build comprehensive unit and integration tests, automate releases via CI/CD, and establish observability patterns for debugging production issues
Collaborate cross-functionally: Work with product, QA, and support teams to clarify requirements, reproduce customer issues, and verify fixes
Mentor and elevate the team: Share deep WASM and Rust expertise through pairing sessions, design reviews, and documentation that helps the broader SDK team level up
Produce and maintain documentation: Write clear API references, integration guides, and code examples that help developers onboard quickly and use the SDK effectively
Qualification
Required
5+ years building production software with a track record of shipping reliable, performant code in a team setting
Deep Rust experience including familiarity with wasm-bindgen, wasm-pack, or similar tooling. You should have a deep understanding of ownership, lifetimes, and tokio executors
Proven WebAssembly expertise with hands-on experience compiling Rust to WASM and integrating with JavaScript
Strong JavaScript/TypeScript fluency and comfort designing ergonomic, type-safe APIs
Browser platform knowledge including understanding of the event loop, memory management, Web Workers, and cross-browser compatibility challenges
Strong testing discipline (unit, integration, E2E browser testing, CI pipelines)
Clear, concise communication—especially in async, written form
Preferred
Experience building or maintaining SDKs, libraries, or developer tools consumed by external developers
Experience with UniFFI, cbindgen, or other binding generators
Familiarity with bundlers (Webpack, Vite, Rollup) and their interaction with WASM modules
Background in peer-to-peer networking, WebRTC, or real-time synchronization systems
Experience with WebAssembly threading, SIMD, or other advanced WASM features
Prior work optimizing for memory-constrained or performance-critical environments
Benefits
Health, dental, vision, life, and disability insurance
401(k)
Flexible spending accounts
Private healthcare through Vitality
A pension plan
Region-specific coverage
Flexible time off
Company
Ditto
Ditto allows teams to collaborate on consistent and effective copy.
2-10 employees
H1B Sponsorship
Ditto has a track record of offering H1B sponsorships. Please note that this does not
guarantee sponsorship for this specific role. Below presents additional info for your
reference. (Data Powered by US Department of Labor)
Distribution of Different Job Fields Receiving Sponsorship
Represents job field similar to this job
Trends of Total Sponsorships
2022 (1)
2020 (3)
Funding
Current Stage
Early StageTotal Funding
$13.85MKey Investors
Craft VenturesY Combinator
2026-01-20Series A· $12.2M
2021-06-01Seed· $1.5M
2020-03-16Pre Seed· $0.15M
Leadership Team
Jessica Ouyang
Co-Founder
Jolena Ma
Co-Founder
Recent News
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