We are looking for a Senior Rust engineer who can design, build, and optimise Wasm modules that integrate with our MuleSoft-based integration layer and external billing APIs. You will join a tight, high-trust squad led by an experienced Team Lead and work on-site in Makati two to three days per week, with the remaining days remote.

Key responsibilities

Design, code, and maintain high-performance Rust libraries and binaries that compile to WebAssembly and run under WASI in production.

Build new features for AX1’s invoice, payment, and policy APIs, ensuring secure input validation and error handling in accordance with enterprise API-policy standards.

Optimise memory-safe, low-latency data pipelines that process high-volume billing events in near-real time.

Collaborate with integration engineers to expose Wasm modules through MuleSoft; MuleSoft knowledge is appreciated but not mandatory.

Review pull requests, mentor peers, and help establish best practices for Rust/WASI development and API governance.

Troubleshoot performance issues, write unit and integration tests, and contribute to CI/CD pipelines for Wasm artefacts.

5+ years’ professional software-engineering experience, with at least 2 years in Rust building production services or libraries.

Proven track-record shipping WebAssembly or other performance-critical modules in a cloud or edge environment.

Solid grasp of async Rust, Cargo workspaces, and common crates (Tokio, Serde, anyhow, reqwest, etc.).

Experience designing or consuming RESTful or event-driven APIs; familiarity with policy enforcement (rate-limits, authZ, schema validation) is a plus.

Ability to ramp up quickly on complex code-bases and deliver incremental value from day one.

Comfortable working in a hybrid setup and collaborating across time zones.

Nice-to-have

Exposure to MuleSoft Anypoint Platform or other ESB/iPaaS tools.

Background in fintech, insurance, or large-scale billing systems.

Knowledge of API-policy definition in Kong, Apigee, or similar gateways.