Senior​/Software Engineer; AI Agents

Senior / Staff Software Engineer (AI Agents)

Join to apply for the Senior / Staff Software Engineer (AI Agents) role at Actively AI.

Our thesis is that businesses of the future will be powered by agentic human‑in‑loop machines that make every business function 10x more efficient. Actively AI is building that super‑intelligent machine for Enterprise GTM organizations, focused on increasing productivity per rep. We power the day‑to‑day for outbound teams at dozens of companies like Samsara, Ramp, Verkada, and Ironclad. Because revenue is the ultimate fuel for businesses, the hundreds of millions of dollars we generate for our customers enables them to employ more people, innovate faster, and deliver more value to their customers.

In addition to top‑notch customers that love our product, our team is incredibly high‑caliber — the co‑founders are former Stanford AI researchers and the engineering team comes from Harvard, CMU, Berkeley, Brex, Scale AI, and Google. We're also backed by top investors, including Bain Capital Ventures, First Round Capital (seed investors in Uber, Square, Roblox, Clearbit), Lachy Groom, and Stanford AI faculty.

We have a very ambitious product and scaling roadmap, strong market interest, and it’s time to put the foot on the gas. If you get excited by the thought of working really hard on these kinds of problems with a high‑caliber team, then Actively AI is the right place for you.

We’re looking for a Senior/Staff Backend Engineer to architect and build large‑scale systems that power Actively’s GTM AI agents. These agents continuously reason over real‑time customer and external data, generate next‑best actions, and execute them reliably across systems with humans in the loop. In this role, you’ll design the scalable, event‑driven, and fault‑tolerant infrastructure that makes this intelligence possible — integrating with LLMs, orchestrating complex workflows, and ensuring every action happens with high reliability.

This is a foundational role, shaping how production‑grade agents operate at enterprise scale.

• Design and build the agents that power Actively’s platform. Model complex customer and business workflows into clear, reliable agent logic that reasons over streaming data, maintaining state, decides what to do next, and acts consistently across systems — continuously and at massive scale.
• Develop orchestration and workflow primitives for agent and human collaboration. Translate nuanced, long‑running real‑world scenarios — multi‑step workflows, customer‑specific rules, and human‑in‑the‑loop actions — into well‑structured agent behaviors that are predictable, maintainable, and easy to extend.
• Ensure reliability through good modeling. Design agents with clear state transitions, strong data contracts, and explicit guarantees — embedding observability and fault tolerance into their design so they behave correctly over millions of events and long‑lived sessions.
• Continuously evolve agent design. Simplify complex behavior through better abstractions, documentation, and testing — ensuring agents remain reliable and comprehensible as capabilities, data volume, and concurrency grow.

• Experienced systems builder. You’ve designed and operated large‑scale, event‑driven backend systems — modeling complex, long‑lived workflows into clear, maintainable, and reliable software.
• Strong backend engineer. Deep Python expertise and solid fundamentals in concurrency, transactions, and performance tuning.
• Architectural thinker. You reason about trade‑offs between consistency, latency, fault‑tolerance, and cost — building for correctness and adaptability.
• Product‑minded. You care about usability, developer experience, and how system design translates into real customer value.
• Fluent in modern infrastructure. Familiar with streaming and workflow technologies (Kafka, Pub/Sub, Temporal‑like), and data stores across relational, in‑memory, and vector paradigms.
• Collaborative and pragmatic. You value iteration, clear communication, and helping others move faster without sacrificing quality.
• Curious about AI systems. You’re excited by how LLMs, retrieval…