Founding Quality Engineer

ABOUT SIRIUS Sirius builds secure computing and networking technology for defense, intelligence and critical national infrastructure. Our core product is Crux, a lightweight secure networking platform that connects phones, laptops, servers, embedded systems and tactical devices across untrusted networks. Crux runs on Android, iOS, Windows and Linux, with embedded and OpenWrt targets, and is centrally managed through Crux C2. It is designed for environments where networks are unreliable, infrastructure is limited and the consequences of failure are real. Crux is already in operational use and has been developed through customer deployments, our partnership with Arqit and UK Government-supported R&D with HMGCC. We are now extending the platform toward the assurance and certification regimes required by defense and national-security customers, including a standards-conformant IPsec/IKEv2 implementation alongside our existing WireGuard-based stack. Alongside Crux, Sirius develops secure edge hardware for environments where performance, size, weight, power and assurance all matter. We are still a small company. Sirius operates across the United States, United Kingdom and Germany, and the founders remain closely involved in designing, building and shipping the product. This is one of our first engineering hires outside the founding team, so the person joining us will have an unusually large influence on how the company builds software. THE ROLE We have reached the point where product quality can no longer live primarily in the heads of the engineers who built Crux. There is working software, active deployments and a team that ships frequently. There is also a growing matrix of operating systems, device types, server versions, network conditions and assurance requirements that needs to be tested systematically rather than through engineering intuition. That is why we are hiring our first Quality Engineer. You will build the test and quality engineering capability for Crux from the ground up. You will decide what should be tested, how it should be automated, and where it fits into the development and release process. This is not a manual QA role and it is not a position where you inherit somebody else's test plan. You will write software, build infrastructure, design test environments, break distributed systems deliberately and work directly with the engineers building Crux to make it harder to ship defects in the first place. For a while, you will be the quality engineering function at Sirius. WHAT YOU WILL WORK ON Crux is a distributed system spanning servers, management infrastructure and clients running across Android, iOS, Windows, Linux and embedded devices. Those components have independent release cycles and, in the real world, are rarely all running the same version. You will build and own a variety of quality-related engineering processes, including: End-to-end system testing across Crux C2, servers and endpoint clients. Cross-version compatibility testing, proving that supported combinations of old and new clients, servers and management components continue to work together. Network and failure testing, including packet loss, high latency, partitions, loss of individual components, interrupted upgrades and recovery. Security lifecycle testing, including provisioning, authentication, key rotation, revocation and device quarantine. Upgrade and rollback testing across desktop, mobile and embedded platforms. Performance baselines for throughput, latency, memory, CPU and other resource constraints. Mobile and device automation using real devices, emulators and appropriate device farms. Embedded test environments for platforms that cannot be treated like another cloud workload. Vulnerability scanning and security testing integrated into CI/CD. External penetration-test coordination, including scope, environment preparation, findings and remediation. Release evidence and assurance artifacts that can be handed to customers, auditors and certification bodies without reconstructing them after the fact. Test infrastructure hardening, configuration auditing and logging so that the environment producing the evidence can itself be trusted. Over time, we expect much of this capability to become infrastructure: repeatable test environments, automated network impairment, reproducible device configurations and release gates backed by evidence. HOW WE WORK Sirius is deliberately small. You will work directly with the founders and development team. There is very little organizational distance between identifying a problem and changing the product. You will also have direct exposure to the organizations using Crux. Many operate in defense, intelligence and critical infrastructure environments, and their requirements are often driven by operational constraints rather than conventional enterprise IT. Understanding those conditions matters. A test that proves something works on a perfect network is useful. A test that proves what happens when a radio link disappears halfway through a key rotation is much more useful to us. We also use coding agents extensively throughout engineering. They are part of the normal development environment at Sirius: exploring unfamiliar code, generating test scaffolding, refactoring, analyzing failures, producing documentation and accelerating repetitive engineering work. We do not treat an agent's output as correct because it produced it quickly. Knowing how to specify the problem, constrain the work, verify the result and recognize when human reasoning is more useful is part of engineering here. YOUR FIRST 90 DAYS We expect you to arrive with opinions. During your first month, you should understand the architecture of Crux, how we currently test it, where failures are most consequential and where our largest gaps sit. By around 60 days, we would expect the beginnings of a repeatable end-to-end test environment, automated compatibility testing in CI and several meaningful failure scenarios running without manual intervention. By the end of your first 90 days, we want to be able to show a customer or assurance reviewer not simply that we believe a release is good, but the evidence explaining why. The exact architecture of that system is yours to propose. WHAT WE ARE LOOKING FOR You do not need to match every item below, but this role probably suits someone who has spent several years testing complex software systems and wants to own the problem rather than one part of the test suite. You should have experience with several of the following: Building automated test infrastructure for a distributed, networked or security-sensitive system. Starting with little or no existing test estate and deciding what should exist. Systems where clients and servers have independent release cycles. CI/CD pipelines and reproducible test environments. Containers, virtual machines and network simulation or impairment. Mobile automation, emulators, simulators or physical device farms. Linux systems and enough networking knowledge to reason about routes, interfaces, tunnels, DNS, packet flows and failure conditions. Security testing, vulnerability management or penetration-test remediation. Producing test evidence for customers, auditors, regulators or certification programs. Writing production-quality software rather than relying entirely on test-specific scripting. Experience with WireGuard, IPsec/IKEv2, VPNs, zero-trust networking, cryptographic systems, or embedded Linux would be particularly useful. THE KIND OF ENGINEER WHO SUCCEEDS HERE You care about evidence. If we say Crux behaves a certain way, you want a repeatable test that proves it. You are a builder. An empty repository and a difficult systems problem are more interesting to you than maintaining a mature test suite somebody else designed. You are pragmatic about quality. The objective is not maximum test coverage or an impressive dashboard. It is finding the failures that matter before our users do. You are comfortable challenging assumptions, including those made by the people who wrote the system. You can move between software engineering, networking, security and infrastructure without requiring those problems to belong to different teams. And you are interested in how the product is actually used. The operating environment matters at Sirius because the behavior of the system when things go wrong is often more important than its behavior when everything is working normally. COMPENSATION AND BENEFITS Base salary: $80,000 - 110,000, depending on experience Equity in an early-stage company 100% individual premium coverage for medical, dental and vision insurance 401(k) with immediate eligibility Flexible paid time off Fully remote within the United States More unusually, you will have the opportunity to design an engineering function rather than inherit one, and to see the systems you build become part of how Sirius develops, assures and releases Crux. LOCATION AND ELIGIBILITY This position is fully remote within the United States. Because of the customers and programs we support, candidates must be United States citizens and normally resident in the United States. Sirius is unable to provide visa sponsorship for this position now or in the future. Sirius Computer, Inc. is an equal opportunity employer.