Senior Rust Engineer – System, Proxy Hardening & Infrastructure

The Role

The Senior Rust Engineer – System, Proxy Hardening & Infrastructure will own production hardening, performance validation, and infrastructure operations for Securly's Rust web filtering proxy — establishing the reliability and scalability baseline that millions of students depend on, and owning the on-premise Docker proxy appliance for school network environments.

Your mission is to ensure the proxy performs, scales, and deploys reliably in production. You will own canary rollout configuration, CloudFormation-based scaling infrastructure, load testing strategy, and performance baseline definition. You will also own the on-premise Docker appliance — a lightweight Rust proxy deployed in school network environments that intercepts TCP traffic and prepends identity headers.

At L5, this is not purely an infra-execution role. You are expected to identify systemic reliability risks in the proxy stack and propose architectural mitigations, not just react to incidents. You define what 'production-ready' means and enforce that bar.

What It Means to Be L5 at Securly

L5 at Securly is a Staff Engineer. You are the technical owner, not just an implementer.

• Drive technical direction for your initiative end-to-end: from architecture to production, with minimal oversight from your engineering manager.
• Identify and resolve ambiguity in requirements, system boundaries, and design tradeoffs without waiting for a fully-formed spec.
• Mentor L3/L4 engineers on the team: code reviews, design feedback, pairing, and raising the bar for what production-quality work looks like.
• Partner with your L6 technical lead and the Distinguished Engineer on architectural decisions, surfacing tradeoffs clearly rather than deferring them upward.
• Contribute to cross-team engineering standards: you are expected to influence practices beyond your immediate squad.
• Translate technical context into clear written artifacts that non-engineers (PM, Support, Leadership) can act on.
• Participate in on-call rotation and own the full incident lifecycle for your system: detection, diagnosis, resolution, and retrospective.

What You'll Do

• Define what 'production-ready' means for the Rust proxy: establish written performance baselines, reliability criteria, and the specific metrics that trigger a rollback vs. a hotfix.
• Design and execute load tests to identify performance bottlenecks; profile memory and CPU under peak and sustained load; produce baseline documents the team references across deployments.
• Own canary rollout configuration and CloudFormation-based ASG scaling policies — modify templates, configure health checks, tune scaling behavior; document every configuration decision with rationale.
• Identify and propose mitigations for known proxy infrastructure risk areas including Redis behavior under peak throughput, CORS/proxy transparency edge cases, and connection pool exhaustion.
• Maintain and harden the on-premise Docker proxy appliance — image builds, container networking, minimal image design, and distribution to school network environments.
• Investigate and resolve production performance issues under peak load; produce written post-mortems that close the loop on root cause.
• Build monitoring, dashboards, and alerting for proxy infrastructure (CloudWatch, Splunk); define SLO targets and ensure alerting is calibrated to them.
• Contribute to C++ to Rust business logic conversion work alongside the Proxy Conversion engineer.
• Support TCP stream handling and socket-level work for the on-premise appliance: bidirectional forwarding, port interception, identity header injection.

Skills & Requirements

Who You Are

• You take performance personally — you do not accept 'probably fast enough.' You profile, you measure, you prove it — and then you write it down.
• You have owned production infrastructure and understand that canary rollouts, health checks, and scaling policies are not afterthoughts — they are the job.
• You are comfortable in the systems layer: TCP streams, socket programming, and container networking are familiar territory.
• You identify systemic risks before they become incidents. You advocate for reliability improvements over tactical fixes.
• You produce written artifacts — post-mortems, baseline documents, SLO definitions — that outlast any individual incident or sprint.
• You operate well in an environment where production stability is a shared responsibility and on-call is part of the role.

About Securly

Benefits