[Remote] Senior/Staff Software Engineer (Full-Stack Engineer)

Note: The job is a remote job and is open to candidates in USA. Actively AI is focused on building superintelligent machines for Enterprise GTM organizations, enhancing productivity for outbound teams. The Senior/Staff Full Stack Engineer will architect and build foundational systems for user interaction with AI agents, ensuring seamless integration and high-performance customer-facing experiences.ResponsibilitiesOwn end-to-end features. Design, build, and ship customer-facing experiences across the stack, from Python/FastAPI services and background workers to polished React/TypeScript UIsDefine Actively’s product platform. Architect the frameworks, patterns, and shared product components that make every product surface fast, consistent, and cohesiveDesign and prototype intelligent AI interactions. Collaborate with agent SDKs and internal frameworks to build new user experiences for configuring, debugging, and collaborating with agents including conversational interfaces, feedback loops, and workflow buildersBuild for real usage at scale. Operate across the full stack to ensure high performance, reliability, and seamless data flow, working across SQL/NoSQL stores, caching layers, and task execution pipelines, and contributing to backend systems where needed to deliver a cohesive end-to-end experienceCustomer-driven iteration. Work directly with customers and alongside other teams to translate real feedback and behavior into simple, easy-to-use experiences, experimenting and refining quickly based on what customers actually needSkills5+ years of experience building and shipping high-impact, customer-facing products end-to-end — from backend APIs to refined UI experiencesCare about usability, polish, and the emotional feel of software as much as the systems behind itDeep experience with React, TypeScript, and modern web frameworksComfortable working in Python/FastAPI backends to craft seamless full-stack flowsRecognize the patterns behind good architecture and design frameworks that help others move faster without sacrificing qualityThink in terms of type safety, API contracts, and shared platform primitivesThrive in fast feedback loops; building, learning, and refining quickly based on real-world use and customer insightThrive in environments where the path isn't fully defined — making architectural and product calls without waiting for direction, owning outcomes end-to-end, and bringing structure to ambiguityHave shipped real AI-powered products and not just prototypes and know how to turn LLM capabilities into fast, trustworthy, user-facing experiencesStay current on the ecosystem because you're building with it, not just watching itTrack record of building 0→1 products in fast-moving, resource-constrained environmentsExperience as an early or founding engineer, where you owned architecture, product calls, and shipping and not just executionDeep experience building agentic UI systems, such as chat interfaces, agent inboxes, or task orchestration UIsCompany OverviewAI agents for GTM. Deploying per-account agents that work 24/7 across your TAM. Powering AEs, AMs, SDRs, and Leaders across the Enterprise. It was founded in 2022, and is headquartered in New York, New York, USA, with a workforce of 51-200 employees. Its website is https://www.actively.ai.Company H1B SponsorshipActively AI has a track record of offering H1B sponsorships, with 2 in 2025, 2 in 2024, 3 in 2023. Please note that this does not guarantee sponsorship for this specific role.