Promptfoo

Promptfoo is a developer-focused software company that builds tools for teams working with large language models. Its core focus is helping engineers evaluate, test, and compare prompt and model behaviour in a structured way, so that AI features can be improved with evidence rather than guesswork. In practice, that means supporting workflows where teams run repeatable checks against different prompts, models, and configurations, track changes over time, and catch regressions before they reach production. For job seekers, it is the kind of company operating close to the day to day reality of shipping AI powered product features, where reliability, measurement, and developer experience matter.

The product is aimed at people building with LLMs inside real applications, including software engineers, ML engineers, and product teams who need confidence that an AI feature is performing as intended. It is likely to be used by organisations experimenting with multiple model providers, iterating quickly on prompts, or trying to standardise quality across teams. The audience is practical and technical, and the value is clearest when AI is not a demo but a maintained part of a product that needs consistent behaviour, sensible guardrails, and clear ways to assess output quality.

Within the SaaS ecosystem, Promptfoo sits in the emerging layer of tooling around AI development and operations, alongside observability, evaluation, and testing platforms that have grown in importance as LLMs move into production. Rather than competing with model providers, it complements them by helping teams choose between models, validate changes, and build confidence in their AI systems. That position suggests a company that needs to stay close to the rapidly changing AI tooling landscape, while still prioritising solid software engineering fundamentals.

People who thrive at Promptfoo are likely to enjoy building developer tools, working on product surfaces that need to feel fast and intuitive, and thinking carefully about how to measure something that is partly subjective. Strong skills in TypeScript or JavaScript, backend engineering, CLI and tooling design, and an interest in evaluation methods and testing practices would be relevant. Because the space is evolving quickly, comfort with ambiguity, curiosity about new model capabilities, and a willingness to iterate with feedback from technical users are likely to be important.

What may appeal to candidates is the chance to work on a product that sits at the centre of how modern teams ship AI features, with a direct line to developer needs and a clear problem to solve. The work is likely to be product led and engineering heavy, with a strong emphasis on practical utility, clear documentation, and making complex workflows feel manageable. If you like building tools that other engineers rely on, and you want to contribute to the infrastructure that makes LLM based software more dependable, Promptfoo is the sort of company that could be a good fit.