Senior Full Stack Engineer

Senior Full Stack Engineer Location: Remote (Global) Team: Core Engineering Summary You'll be one of two engineers building the foundational systems that power a next-generation lead certification platform — a browser-embedded session capture script, a high-throughput certificate ingestion backend, a real-time lead scoring engine, and a SaaS dashboard for customers. This is a core builder role: you'll own hard problems across the stack, from sub-4KB JS embeds running on third-party sites to immutable certificate storage at scale. Expect depth, trade-off discussions, and zero hand-holding. Requirements (Must-Haves) Excellent English communication skills — you'll interact directly with the client team and need to articulate technical decisions clearly and confidently 5+ years of full-stack engineering experience in production environments, with demonstrable ownership of backend systems at scale Strong backend engineering fundamentals: you've designed and operated ingestion pipelines with queuing, deduplication, idempotency, and failure handling — and you can talk through the trade-offs without prompting Deep understanding of storage strategies for immutable, append-only records — you know when Postgres is the wrong answer and why, and you can reason about audit trails, certificate schema design, and query patterns across relational, document, and time-series options Proven experience building and optimizing frontend JS for performance-critical contexts: tree shaking, minification, async loading, avoiding render-blocking — you treat bundle size as an engineering constraint, not an afterthought Solid understanding of how browsers handle third-party scripts: CSP policies, CORS, ad blockers, script injection vectors — you know what can go wrong and how to design around it Experience with real-time data pipelines: you can reason about where latency comes from, where parallelism helps, and how to keep a scoring engine responsive under load Comfortable designing for scale from the start — batching, compression, and streaming from the browser aren't things you look up; they're things you build Requirements (Nice-to-Haves) Experience with session recording or behavioral analytics products (Heap, FullStory, Hotjar, or equivalent) Familiarity with certificate issuance systems, signing workflows, or cryptographic audit trails Experience building multi-tenant SaaS dashboards with per-customer config, access controls, and analytics Exposure to lead scoring models or behavioral signal processing in a B2B context Experience with TypeScript in both frontend and backend contexts Familiarity with Kafka, SQS, or similar message queuing systems for high-throughput ingestion Bonus Points Security instincts around high-value attack surfaces — you can articulate the risks of script injection, certificate forgery, replay manipulation, and artifact signing without being prompted Awareness of TrustedForm's architecture (open certificate URLs) and the ability to explain why access-controlled certificate delivery matters and how to implement it correctly Contributions to open source tooling in performance, observability, or security domains Prior experience at a company that built embedded JavaScript products (tag managers, tracking pixels, live chat widgets)