Senior Full-Stack WebApp Engineer

SUMMARY Level is a learning technology company dedicated to helping students build real academic and life skills with confidence and joy. We combine proven curriculum principles with world class interactive design to make meaningful practice something students want to come back to, not something they struggle through. We support what teachers, schools, and parents are already doing by increasing student engagement with high quality, standards-aligned practice that reinforces classroom learning. As a Senior Full-Stack WebApp Engineer on the Platform team, you will own end-to-end slices of Level's web experience — from the browser through the API layer and into the services that power identity, accounts, onboarding, and the authoring/admin surfaces our internal teams rely on. You will architect and ship features that span TypeScript front-ends (React-family) and Kotlin/Java (JVM) backend services, partner with engineers across web, mobile, and native clients, and help raise the engineering bar on a small, senior-leaning team. Your work will directly impact the experiences students, educators, and internal users have every day, and the velocity at which the rest of the engineering organization can build on top of the platform. This is an onsite role (5 days per week) WHAT YOU WILL DO Feature Development - Own full-stack feature delivery across the web client and its supporting backend services — from UX and component work down through API design, data modeling, and persistence. - Design and evolve platform-facing web surfaces — authentication, account capture, invitation and onboarding flows, embedded authoring, and admin tooling consumed by web, mobile, and native clients. - Implement clean, readable, testable code on both client and server; take responsibility for features from initial design through release and ongoing maintenance. Architecture & Backend Services - Architect and implement backend services and APIs (REST and gRPC) that back the web experience and are reused across product surfaces. - Make explicit trade-offs on data modeling, contract design, and service boundaries; partner with backend architects on shared libraries and patterns. - Contribute to platform direction through RFCs, architecture reviews, and decisions about shared libraries, frameworks, and developer tooling. Performance, Reliability & Security - Define and own reliability targets (SLOs/SLIs) for the services you own; implement structured logging, metrics, and tracing on top of platform standards. - Profile, optimize, and tune both client and server for latency, throughput, and cost efficiency — Core Web Vitals on the front-end, p95/p99 on the back-end. - Apply web security fundamentals (auth flows, session/token handling, CSRF, CORS, content security) with particular care for student data and K-12 privacy requirements. - Participate in incident response and post-mortems for what you own. Collaboration & Delivery - Partner with product, design, mobile, and infrastructure engineers to translate product intent into concrete technical designs and ship them iteratively. - Participate actively in planning, technical discussions, code reviews, and release processes — contributing practical input on feasibility, trade-offs, and implementation details. Code Quality & Technical Ownership - Ensure high standards of performance, stability, and test coverage across the web surfaces and services you own; partner with our DevProd lead on test strategy, CI/CD, and performance benchmarks. - Actively contribute to improving web architecture, technical foundations, and developer experience. - Identify and address technical debt, production issues, and scalability concerns — leave the code better than you found it. - Mentor mid-level and associate engineers through pairing, code reviews, and technical guidance; help shape the conventions and patterns the rest of the team adopts. QUALIFICATIONS Need to Have: - 5+ years of professional full-stack web engineering experience shipping production systems used by real users. - Strong proficiency with TypeScript and a modern component framework (React preferred — React Native experience a plus given our direction on client shells); state management, accessible UI patterns, and performance optimization in the browser. - Strong backend proficiency in Kotlin or Java on the JVM (Kotlin is Level's primary backend language) or TypeScript for shared platform libraries and tooling; comfort designing and operating long-lived services. - Solid understanding of HTTP, REST, and gRPC + protobuf — Level's primary service-contract framework, with Backstage as the service catalog. - Experience with PostgreSQL and data modeling for product features; familiarity with key-value / document stores (DynamoDB, Redis) and with caching, queues, and eventual-consistency trade-offs. - Working knowledge of AWS, containers (Docker / Kubernetes), and CI/CD pipelines as a consumer — you don't need to own clusters, but you should be effective in them. Familiarity with Linkerd, ArgoCD, Terraform is a plus. - Strong testing discipline — unit, integration, and end-to-end — and a track record of partnering with QA/DevProd to ship reliably. - Excellent written and verbal communication; ability to lead design discussions, write clear RFCs, and represent technical trade-offs to non-engineering stakeholders. Nice to Have: - Experience with authentication and identity systems — OAuth/OIDC, SSO, session and token management, third-party providers (Google, Discord, Apple, etc.). - Experience building authoring tools, CMSes, or internal back-office applications used by editorial/operations teams. - Familiarity with OpenTelemetry, structured logging, and modern observability stacks (SigNoz — Level's stack — Grafana, Datadog). - Background in EdTech, K-12, or other domains with strong privacy and accessibility requirements (FERPA, COPPA, WCAG). - Experience contributing to or maintaining shared design systems and component libraries. - Exposure to Backstage, internal developer platforms, or other developer productivity surfaces. SCORECARD Mission Ship and operate the web-facing slices of Level's platform — identity, onboarding, authoring, and admin — at a quality bar that lets every other product team build on top with confidence.