Staff Application Engineer

**About CertifyOS** CertifyOS is building the data infrastructure that powers modern healthcare. Today, healthcare organizations rely on fragmented and outdated provider data. This creates unnecessary administrative work, regulatory risk, and higher costs across the system. We’re solving that problem. Our API-first platform automates provider licensing, enrollment, credentialing, and network monitoring by connecting directly to hundreds of primary data sources. We help healthcare organizations maintain accurate, compliant, and reliable provider networks at scale. Our vision is simple: **One API. One provider ID. Frictionless provider data.** We’re backed by leading investors and built by a team with deep experience in provider data systems. At CertifyOS, we value authenticity, accountability, collaboration, results, and openness to feedback. We’re building a high-ownership team focused on solving real infrastructure problems that impact millions of patients. **About the Role** We’re looking for a Staff Software Engineer to own the application layer of the CertifyOS platform the full-stack systems that translate our provider data infrastructure into products that payers, health systems, and digital health companies actually use. This is a Staff-level role with real architectural scope. You won’t be handed a spec you’ll define how the application layer is structured, how the frontend and backend evolve together, how API contracts are designed for external consumers, and how the engineering practices that govern application development scale with the team. You’ll drive technical strategy, shape engineering culture, and set patterns that other engineers build on. **Problems You’ll Solve** CertifyOS is an API-first platform with an increasingly complex product surface. As we scale more integrations, more enterprise customers, more AI-powered workflows the application layer has to evolve without accumulating the kind of technical debt that kills product velocity. **How do you build a frontend that scales with product complexity without becoming unmaintainable?** React and TypeScript at the component level is straightforward. At Staff level the problem is harder: design systems, state management strategy, API contract alignment between frontend and backend, and a component architecture that lets a growing team move fast without stepping on each other. **How do you design API contracts that serve both internal product teams and external enterprise consumers?** CertifyOS APIs are external-facing products, not just internal plumbing. You’ll define versioning strategy, resource modeling, error semantics, and pagination patterns that work for enterprise integrations with complex compliance requirements and evolve without breaking existing consumers. **How do you deliver a polished enterprise product experience on top of complex, async data workflows?** Provider credentialing and enrollment are long-running, multi-step processes. You’ll architect the application patterns optimistic UI, async job tracking, real-time status updates via WebSockets or SSE that make these workflows feel fast and reliable to end users even when the underlying operations aren’t. **How do you keep application performance and reliability high as the data layer grows?** As our Spanner and BigQuery footprint scales, the application layer is where query latency, pagination strategy, and caching architecture either absorb or amplify that complexity. You’ll own the performance boundary between the data layer and the product. **How do you integrate AI capabilities into the product without compromising UX or reliability?** We’re building AI-powered workflows into the platform agents, LLM-assisted credentialing, intelligent data surfacing. You’ll define how those capabilities integrate into the application layer: latency handling, fallback behavior, streaming UX patterns, and eval instrumentation that surfaces quality issues in production. **What We’re Looking For** **Staff-level ownership & technical leadership** - 8+ years building production full-stack systems, with demonstrated impact at Staff or Tech Lead level - Track record of setting technical direction you’ve defined the architecture others built on, not just executed someone else’s design - Proven ability to influence engineering practices across teams without direct authority through design docs, code review, and technical credibility - Experience leading cross-functional technical initiatives involving product, design, and backend engineering simultaneously **Full-stack architecture depth** - Deep backend expertise in Java or a comparable strongly-typed language service design, API contract modeling, performance optimization, and reliability engineering in production systems - Strong frontend architecture skills in React and TypeScript component system design, state management at scale, build tooling, and the tradeoffs between client-side rendering, SSR, and static approaches - Experience designing and evolving external-facing APIs under active consumers: versioning, backward compatibility, error semantics, and developer experience as a first-class concern - Fluency across API paradigms REST, GraphQL, gRPC, WebSockets, SSE and the judgment to choose the right one based on consumer needs and operational constraints **Enterprise product & integration patterns** - Experience building application layers for enterprise B2B products multi-tenancy, role-based access control, audit logging, and the compliance surface area that comes with handling PHI/PII - Experience with async workflow patterns in product UIs long-running jobs, real-time status, optimistic updates, and the UX patterns that make complex backend processes feel responsive - Understanding of SOA and microservices boundaries from an application perspective you’ve designed service contracts and managed the coupling and versioning tradeoffs that come with them **Performance, reliability & observability** - Strong instincts for application-layer performance: caching strategy, pagination design, N+1 query patterns, and where the frontend vs. backend boundary should sit for a given workload - Experience defining and owning SLOs for user-facing systems not just backend uptime, but real user experience metrics: TTFB, interaction latency, error rates - Experience building observability into application systems distributed tracing, structured logging, and frontend error tracking that gives you signal when something breaks in production **AI-era engineering** - Experience integrating AI/LLM capabilities into production application layers streaming UX, latency handling, fallback behavior, and eval instrumentation for non-deterministic outputs - Fluency with AI-assisted development tools (Cursor, Claude Code, MCP servers) this is part of how we work, not a nice-to-have - In an AI-augmented environment, you write less and review more you use that leverage to tackle harder architectural problems, not just ship faster **Communication & mentorship** - Strong written communication you write design docs that create alignment, not just documentation after the fact - Track record of growing engineers around you through code review, pairing, and technical mentorship - Ability to represent technical tradeoffs clearly to product and non-technical stakeholders **Nice to Have** - Experience with microfrontend architectures or design system libraries at scale - Familiarity with healthcare data standards (FHIR, HL7) or credentialing and enrollment workflows - Experience with feature flagging, A/B testing infrastructure, or progressive rollout patterns - Familiarity with accessibility standards (WCAG) in enterprise product contexts - Experience with cost optimization for cloud-native application deployments - Track record of reducing frontend or backend technical debt through iterative architecture migration **Technologies & Tools** Java 21 / Quarkus · React / TypeScript · GCP (Spanner, BigQuery) · Kafka · REST / GraphQL / gRPC / WebSockets · Docker / Kubernetes · GitHub Actions · Sentry · Cursor / Claude Code / Codex **Benefits of Working at Certify** - At Certify, we’re building with intention and taking care of the people doing the work. - Your well-being matters to us. We provide 100% coverage of health, dental, and vision insurance premiums for employees. Our US-based team benefits from unlimited PTO, with at least two weeks off each year to recharge. In India, employees are supported with health insurance, statutory leave benefits, and additional wellness (menstrual) leave for women. We are an equal opportunity employer committed to building an inclusive environment where everyone feels valued and empowered to do their best work, and we welcome applicants from all backgrounds and experiences. If you require reasonable accommodations during the application process, please contact . We are also committed to pay transparency and foster an open culture where compensation conversations are encouraged and respected.