Backend Engineer

Back to rolesBackend EngineerLocationSan Francisco, CAEmployment typeFull-timeLocation typeOn-siteDepartmentSoftwareCompensation$150K–$400K + equityAbout LightberryLightberry builds the software layer for expressive, interactive robots. We combine voice AI, perception, and behavior systems so robots can understand people and respond naturally.We are a small, hands-on team based in San Francisco, working across software, hardware, design, and research to turn new capabilities into robots people can interact with today.We care about thoughtful craft, fast iteration, and shipping real systems into the world.Robots with SoulsYep, you read that right.Robots are here, but they ship with no software.

They’re all mute, deaf, and blind out of the box. The only way to get the robot to do anything is to write code. This is insane.We want robots to behave like in the movies: proactive, caring, aware.The roleOur robots are reactive in real time: audio, video, and motion stream out of the robot, understanding and behavior stream back in. That pipeline is everything that makes them interactive.A robot can hesitate and still feel alive — it just has to hesitate with intention.

The voice AI stack behind that is already built. You’ll keep it fast, make it smarter, and design the architecture it grows on.In other words: you’re wiring robot brains.What you’ll doOwn the real-time pipeline that streams audio, video, and motion between robots and our voice AI stack.Design the architecture that keeps a growing fleet of robots connected, observable, and fast.Deploy models into the pipeline that turn raw audio into meaning the robot can act on.Hunt latency across the whole path — network, codecs, inference — and win back milliseconds wherever they hide.Debug production the fun way: sometimes the server is a robot standing right in front of you.What’s neededWe don’t care about degrees, titles, or seniority.

Show us hard problems you’ve solved — projects, repos, systems running in production. We do need:Production. You’ve built and operated software at a large scale before.Systems. You’re at home with networking, low-latency pipelines, and architectures that stay simple as they grow.Startups. You’ve worked at a startup or pre-Series B company and are used to owning problems end to end.AI-native. It’s 2026.

We won’t force AI tools on you, but we expect you to learn to get the best out of them — they’re a real multiplier, and people who skip them get left behind.Fun. You write code because you love it — side projects, open source, that tool you built just because.Bonus pointsHardware. You’ve deployed software on robots or hardware before.Models. You’ve shipped ML models into production pipelines.Deep cuts.

You’ve gone below the surface: kernels, codecs, drivers, or open protocols.One last thing…Don’t apply if…You can’t stand chaosYou’d work remotely every day if you couldYou’re not a people-personYou’re pessimistic about tech, AI, and the futureApply if…You want to do your life’s workYou care about developing and expressing your craftYou love intense, fast-paced environmentsYou like getting your hands dirty, no work is beneath youLife’s short, why work on B2B AI SAAS infra slop when you could work on speaking robots?

Apply nowName *Email *LinkedIn profile *Are you legally authorized to work in the United States? *YesNoWill you require visa sponsorship now or in the future? *YesNoGitHub, portfolio, publications, or hardware projectsWhat have you made that you’re proud of? Why? *Submit application