Founding Engineer, Pendulum

• 5+ years of backend engineering experience, with strong expertise in Python. Deep experience with FastAPI or similar Python web frameworks is a must.
• Experience building and scaling LLM-powered applications, particularly those involving visual AI, agentic workflows, or voice-based AI interactions.
• Understanding of asynchronous processing and distributed task execution.
• Familiarity with cloud infrastructure and serverless deployments, preferably on platforms like Modal.
• Strong software engineering experience with the ability to pragmatically think through software design and architecture to ship rapidly while scaling to hundreds of thousands of users.
• You can ship at high velocity without compromising on quality and are comfortable figuring out how to build things you haven't built before.

Desirable

• As an AI engineer at at Pendulum, you will own and scale the backend systems that power our voice-first, AI-driven language learning experience. Your role will be pivotal in developing the infrastructure that enables real-time, multimodal AI interactions. Examples of recent AI engineering work we have shipped include: giving our core conversational LLM agentic abilities to autonomously generate images based on conversational context; implementing memory in our LLM system to make a more personalised language companion, and creating an agentic system to create a ‘Daily Review’ feature that draws from a user’s entire conversational history.
• Design and optimise systems that orchestrate multiple LLMs, voice AI components (TTS, STT), and visual AI to power real-time conversational language learning backed by voice interactions and visual support. This will involve handling streaming responses, profiling and optimising components of chained AI systems, memory management, and agentic workflows.
• Own and scale our FastAPI-based backend, ensuring performance and reliability as we grow to hundreds of thousands of users
• Develop and scale WebRTC-powered voice interactions, leveraging and modifying open-source frameworks like Pipecat to fit our use cases
• Ensure a smooth developer experience by writing and maintaining clean, well-documented code supported by sensible system design choices

• 30 min intro call with one of the founders
• 1 hour technical interview
• 1 hour call with whole team
• Work with us for a day (fully paid)
• Join the team 💫

Total funding: $3.8m

Pendulum is an immersive language learning company, developing AI products that redefine the very basics of learning a new language. Pendulum develops its products off the philosophy that to truly learn a language, one must experience the culture, differentiating it from the gamified learning of Duolingo and the traditional focus of education on grammar and sentence memorising.