Sr. Full Stack Developer

*Description*
As a Sr. macOS / Full-Stack Developer, you'll be joining this client as they begin building the production prototype of a Computer Use Agent (CUA) - think Codex-style assistant that lives on macOS, observes user activity, and can take actions like typing, navigating websites, and operating apps on the user's behalf.
Responsibilities:
* Build the macOS assistant prototype end-to-end
* Develop the front-end / UI layer using React and JavaScript
* Design and manage Docker environments for the prototype and its dependencies
* Integrate the prototype with the underlying CUA models
* Iterate quickly on prototype features based on research team feedback
* Troubleshoot and debug across the stack
* Document architecture and setup
* Collaborate with research scientists, engineers, and TPMs
*Skills*
MacOS Development, Docker, React, Javascript, Desktop Application Development, Prototype Development, Electron, Swift/Objective-C, Accessibility APIs, Screen Capture APIs, LLM/Agent Framework Exposure, System-Level Scripting
*Additional Skills & Qualifications*
Requirements:
* Bachelor's degree in Computer Science or related field
* 6+ years as a software engineer
* Strong macOS development experience
* Proficient with Docker
* Strong React and JavaScript skills
* Comfortable with Linux and shell scripting
* Excellent problem-solving skills and attention to detail
* Strong communication and collaboration skills
* Ability to work independently and in a team environment
Nice to Have:
* Master's degree in Computer Science or related field
* Electron or other cross-platform desktop framework experience
* Swift or Objective-C experience
* Familiarity with macOS accessibility / automation APIs
* Exposure to LLM-powered agents or Codex-style tools
*Job Type & Location*
This is a Contract position based out of Menlo Park, CA.
*Pay and Benefits*The pay range for this position is $70.00 - $85.00/hr.
Eligibility requirements apply to some benefits and may depend on your job
classification and length of employment. Benefits are subject to change and may be
subject to specific elections, plan, or program terms. If eligible, the benefits
available for this temporary role may include the following:

* Medical, dental & vision


* Critical Illness, Accident, and Hospital


* 401(k) Retirement Plan - Pre-tax and Roth post-tax contributions available


* Life Insurance (Voluntary Life & AD&D for the employee and dependents)


* Short and long-term disability


* Health Spending Account (HSA)


* Transportation benefits


* Employee Assistance Program


* Time Off/Leave (PTO, Vacation or Sick Leave)
*Workplace Type*This is a hybrid position in Menlo Park,CA.
*Application Deadline*This position is anticipated to close on Jul 10, 2026.

About TEKsystems


We're partners in transformation. We help clients activate ideas and solutions to take advantage of a new world of opportunity. We are a team of 80,000 strong, working with over 6,000 clients, including 80% of the Fortune 500, across North America, Europe and Asia. As an industry leader in Full-Stack Technology Services, Talent Services, and real-world application, we work with progressive leaders to drive change. That's the power of true partnership. TEKsystems is an Allegis Group company.

The company is an equal opportunity employer and will consider all applications without regards to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.

About TEKsystems and TEKsystems Global Services


We're a leading provider of business and technology services. We accelerate business transformation for our customers. Our expertise in strategy, design, execution and operations unlocks business value through a range of solutions. We're a team of 80,000 strong, working with over 6,000 customers, including 80% of the Fortune 500 across North America, Europe and Asia, who partner with us for our scale, full-stack capabilities and speed. We're strategic thinkers, hands-on collaborators, helping customers capitalize on change and master the momentum of technology. We're building tomorrow by delivering business outcomes and making positive impacts in our global communities. TEKsystems and TEKsystems Global Services are Allegis Group companies. Learn more at TEKsystems.com.

The company is an equal opportunity employer and will consider all applications without regard to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.

*San Francisco Fair Chance Ordinance:* Pursuant to the San Francisco Fair Chance Ordinance, for all positions located in the city and county of San Francisco, we will consider for employment qualified applicants with arrest and conviction records.

*Massachusetts Lie Detector:* It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.

*Use of Artificial Intelligence (AI):* We may use Artificial Intelligence (AI) to support parts of our hiring process, including sourcing, screening, and evaluating candidates. AI helps assess applications and qualifications, but final decisions are made by our hiring team. By applying, you acknowledge and agree that your application may be reviewed using AI tools.