Senior / Staff Software Engineer (Full-Stack Product)

About the Role

We’re looking for a Senior/Staff Full Stack Engineer to architect and build the foundational systems that define how users interact with Actively’s AI Agents through web interface as well as real-time workflows enabled via Chat.

Historically, Actively has delivered intelligence through integrations like Salesforce and Outreach. As our product evolves, we’re building our own customer-facing platform, a unified interface for configuring, understanding, and collaborating with agents. Actively’s product brings together data, reasoning, and automation to power AI agents that collaborate with humans across every step of the GTM motion. You’ll be part of the team that turns those capabilities into seamless, high-impact product experiences. You can read more about this in our blog post.

In this role, you’ll work across the stack, from backend APIs and workflows to frontend systems and design frameworks,  building the core product surfaces where users configure, understand, and collaborate with agents. You’ll prototype new agent capabilities, launch experiments, and shape the standards that make Actively’s agentic platform feel fast, intuitive, and trustworthy.

This is a highly cross-functional, product-oriented engineering role, combining strong technical depth, product judgment, and design sensibility to define the future of human-AI collaboration.

What You’ll Do

• Own 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 UIs.
• Define Actively’s product platform — architect the frameworks, patterns, and shared product components that make every product surface fast, consistent, and cohesive.
• Design 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 builders.
  
• Build 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 experience.
  Customer-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 need.

Who You Are

• A seasoned, product-minded engineer. You have 5+ years of experience building and shipping high-impact, customer-facing products end-to-end — from backend APIs to refined UI experiences
• Product-minded and design-curious. You care about usability, polish, and the emotional feel of software as much as the systems behind it.
• Frontend-strong, backend-capable. You have deep experience with React, TypeScript, and modern web frameworks (Next.js preferred), and you’re comfortable working in Python/FastAPI backends to craft seamless full-stack flows.
• A systems thinker. You recognize the patterns behind good architecture and design frameworks that help others move faster without sacrificing quality.
• Iterative by nature. You thrive in fast feedback loops — building, learning, and refining quickly based on real-world use and customer insight.
• Grounded and self-directed. You thrive in fast-changing environments, bringing clarity and structure when things are ambiguous — taking ownership, driving outcomes independently, and collaborating effectively across teams.
• AI-curious and experimental. You follow the evolving ecosystem of LLM frameworks, SDKs, and agent architectures, and enjoy finding practical, product-ready applications.

Nice to Haves

• Track record of building 0→1 products in fast-moving, resource-constrained environments
• Experience working on agentic UI systems, such as chat interfaces, agent inboxes, or task orchestration UIs.
• Experience building or experimenting with LLM-powered products, agent SDKs, or human-in-the-loop workflows.

Why Join

It’s not often that you can get in on the ground floor of a well-funded startup that’s scaling very fast. That means that instead of following a playbook, you’ll be writing it. Every single day you will be challenged to identify how we can scale and execute on it. You’ll learn what works when you succeed and what doesn’t when you fail. You'll also be in the trenches with an incredibly high caliber, low-ego group of people that are obsessed with building something great.

Benefits

• 🚀 Competitive Early-Stage Equity
• ⚕ Health, Dental, Vision Coverage
• 💡 Unlimited PTO + Recharge Days
• 🍽️ Catered Lunch on Tuesday & Friday w/ Dinners Everyday!
• 🍿 Fully Stock Kitchen
• 💻 Cutting-Edge Tech & Tools
• 🌴 Annual Off-sites & Monthly Events
• 🚆 Commuter Benefits
• 🏢 Cozy Office in NYC

The base salary range for this full-time position based in New York is: $180,000 - $220,000. 

Note on Pay Transparency:

Actively AI provides an estimate of the compensation for roles that may be hired as required by state regulations. Compensation may vary based on (a) location, as Actively AI factors in specific location when benchmarking compensation for most roles; (b) individual candidate skills and qualifications; and (c) individual candidate experience. Additionally, Actively AI leverages current market data to determine compensation, so posted compensation figures are subject to change as new market data becomes available. The salary, other compensation, and benefits information is accurate as of the date of this posting. Actively.ai reserves the right to modify this information at any time, subject to applicable law.

Actively AI is committed to equal treatment and opportunity in all aspects of recruitment, selection, and employment without regard to gender, race, religion, national origin, ethnicity, disability, gender identity/expression, sexual orientation, veteran or military status, or any other category protected under the law. Actively AI is an equal opportunity employer; committed to a community of inclusion, and an environment free from discrimination, harassment, and retaliation.