Full-Time

Technical Lead

Frontend

Onyx

Onyx

11-50 employees

AI-powered mobile trainer with form feedback

Compensation Overview

$200k - $400k/yr

San Francisco, CA, USA

In Person

Category
Software Engineering (1)
Required Skills
JavaScript
React.js
TypeScript
Next.js
Requirements
  • 4+ years of frontend engineering experience building complex, user-facing applications
  • In-depth experience with JavaScript, TypeScript, React, NextJS and other modern frontend technologies
  • Excellent communication skills and ability to collaborate with cross-functional teams
  • Strong product/design intuition
Responsibilities
  • Doing everything frontend for the default open-source chat interface, enterprise search platform, and agent builder
  • Collaborating closely with the design team + founders
  • Setting frontend priorities and best practices
  • Building an exceptional design / frontend engineering culture
  • Fostering an open-source community; guiding contributors on adding to the frontend
Desired Qualifications
  • Familiar with Python, Postgres
  • Degree in Computer Science or related technical field
  • Previous founder or early engineer at seed/series-A startup

Onyx is a mobile AI-powered personal trainer for at-home workouts. It uses the smartphone camera to track movements, automatically counts reps, and provides real-time feedback on form to prevent injuries and improve effectiveness. It offers personalized workout plans aligned with goals like strength, muscle building, or weight loss, and it tracks progress over time. Its differentiator is real-time form correction and rep counting through computer vision, combined with integrated coaching and progress tracking in one app to support safer, more effective workouts.

Company Size

11-50

Company Stage

Seed

Total Funding

$10.1M

Headquarters

San Francisco, California

Founded

2023

Simplify Jobs

Simplify's Take

What believers are saying

  • Private leaderboard groups with friends boost user engagement significantly.
  • Lifetime subscriptions grant unlimited access to all workouts and tracking.
  • Real-time competition via game-like matchmaking drives retention higher.

What critics are saying

  • Apple Fitness+ AI form correction locks users into ecosystem within 6-12 months.
  • Google Fit pre-installs Gemini rep counting on 2B+ Android devices in 9-15 months.
  • OpenAI GPT-5 API commoditizes camera form correction for competitors in 6-12 months.

What makes Onyx unique

  • Onyx uses smartphone camera for 3D motion capture to count reps accurately.
  • Provides real-time form correction to prevent injuries during home workouts.
  • Offers personalized programs for strength, muscle building, and weight loss.

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Your Connections

People at Onyx who can refer or advise you

Benefits

Remote Work Options

Flexible Work Hours

Unlimited Paid Time Off

Paid Vacation

Health Insurance

401(k) Retirement Plan

401(k) Company Match

Wellness Program

Mental Health Support

Conference Attendance Budget

Professional Development Budget

Stock Options

Company Equity

Parental Leave

Family Planning Benefits

Fertility Treatment Support

Adoption Assistance

Phone/Internet Stipend

Home Office Stipend

Relocation Assistance

Tuition Reimbursement

Professional Certification Support

Growth & Insights and Company News

Headcount

6 month growth

0%

1 year growth

-6%

2 year growth

29%
AiThority
Mar 13th, 2025
Onyx Raises $10 Million To Help Teams Find Knowledge Faster with Open Source AI Agents

Onyx, the first AI deep research agent designed for the workplace, announced today a $10M seed round of funding.

The Business Journals
Apr 3rd, 2024
Here's what you need to know about Y Combinator's 2024 winter batch demo day

Y Combinator seeded more than 250 companies in its current winter batch, which leans heavily into AI. One particular AI subcategory has nearly tripled over the past year.