Summary In this episode Nikunj Bajaj, co-founder and CEO of TrueFoundry, talks about the challenge of building reliable agents on top of inherently variable foundation models. He explores the idea of the agent harness as everything around the model engine: memory and context management, tool and MCP integration, sandboxed code execution, permissions, observability, and guardrails. Nikunj explained how TrueFoundry approaches enterprise AI as a centralized control plane for token traffic, while TrueForge provides an open source, vendor-neutral harness for building agents without locking teams into a proprietary stack. He talks about the complexity of model routing across both the harness and gateway layers, the tradeoffs between unified APIs and provider-specific capabilities, and the architectural decisions that affect cost, accuracy, and reliability. He highlighted the importance of benchmark-driven validation, durable execution, human-in-the-loop workflows, sandbox security, and especially agent identity and least-privilege access across chains of agents. Overall, this was a deep look at harness engineering as an emerging discipline, and why organizations need more than isolated point solutions if they want to operate agents safely, efficiently, and at scale. Announcements Hello and welcome to the AI Engineering Podcast, your guide to the fast-moving world of building scalable and maintainable AI systemsYour host is Tobias Macey and today I'm interviewing Nikunj Bajaj about the challenges of keeping your agents reliable when the underlying models aren't and how your harness can helpInterview IntroductionHow did you get involved in AI?Can you describe what TrueForge is and the story behind it?A substantial amount of focus over the past few months has been on "harness engineering". What are the key aspects of the harness?What are the key challenges of building a harness that works well?How do you define what "works well" means given the massive variety of potential use-cases and operating contexts for an agent?Given the proliferation of harnesses, what are the key factors that someone should be looking at to determine which one to use?What are your opinions on why TypeScript and JS runtimes are such a popular choice for these harnesses?What are the key characteristics that you see in harnesses across different language ecosystems?Can you describe the implementation and architecture of TrueForge?How have the design and goals of the project evolved since you first started working on it?What are the elements of a harness that contribute the most to the cost efficiency, accuracy, and reliability (or lack thereof)?The general wisdom suggests that changing a model while keeping the same prompts for a given use-case can have wildly different outcomes. How accurate is that assumption today?What are the most interesting, innovative, or unexpected ways that you have seen TrueForge used?What are the most interesting, unexpected, or challenging lessons that you have learned while working on TrueForge?When is TrueForge the wrong choice?What do you have planned for the future of TrueForge?Contact Info LinkedInParting Question From your perspective, what are the biggest gaps in tooling, technology, or training for AI systems today?Closing Announcements Thank you for listening! Don't forget to check out our other shows. The Data Engineering Podcast covers the latest on modern data management. Podcast.__init__ covers the Python language, its community, and the innovative ways it is being used.Visit the site to subscribe to the show, sign up for the mailing list, and read the show notes.If you've learned something or tried out a project from the show then tell us about it! Email hosts@aiengineeringpodcast.com with your story.To help other people find the show please leave a review on iTunes and tell your friends and co-workers.Links TrueFoundryTrueForgeFPGA == Field-Programmable Gate ArrayAI GatewayHarness EngineeringMCP == Model Context ProtocolA2A == Agent-to-Agent ProtocolPi Agent HarnessvLLM Semantic RouterTesting PyramidThe intro and outro music is from Hitman's Lovesong feat. Paola Graziano by The Freak Fandango Orchestra/CC BY-SA 3.0