Senior Software Engineer, Onboarding
Justworks
| Company | Justworks |
| Category | Engineering |
| Location | New York |
| Remote | On-site (inferred) |
| Employment | Not stated |
| Level | Senior |
| Salary | Not stated by the employer |
| Posted | 3 Jun 2026 |
| Last verified | 3 Aug 2026 |
| Source | Employer ATS (greenhouse) |
Description
Who We Are
At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people.
We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you.
We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team.
Our Values
If this sounds like you, you’ll fit right in. Who You Are
Are you passionate about system design and development? Do you have experience building, deploying, and maintaining large-scale, distributed applications? Are you ready to take your skills to the next level and join a team of innovative self-starters in a supportive, entrepreneurial environment?
As a Senior Software Engineer, you will be leveraging your experience working within a service-oriented architecture. You will be responsible for separating data and functionality as necessary, and will demonstrate an understanding and use of automated testing as a productivity multiplier. You are eager to learn and passionate about improvement. You want to understand how systems work, and you think about how to make them work even better. You will work closely with product managers, designers and other engineers to scope, design, and build new features and functionality. You will be working primarily on backend systems. We’re currently using Ruby on Rails as our main language, but prior experience in RoR is not a requirement.
Your Success Profile
What You Will Work On
The Onboarding teams transform a weeks-long, support-heavy onboarding process into a fully self-serve experience, leveraging AI-powered data ingestion and real-time validation to take companies from signed contract to running payroll in a matter of days. A core part of this work is unifying how people join Justworks — today, full-time, contractor, and international hires across PEO, ASO, and EOR each follow entirely different flows, and this role brings them all into one. Ultimately, this is about building the first product experience every new customer has. If onboarding feels hard, nothing else matters — making this role a direct driver of activation rate, time-to-first-payroll, and onboarding completion.
Collaborate with a cross functional team to design a next-generation platform to unlock new business capabilities
Take ownership of designing and implementing APIs, systems integrations and backend services
Promote engineering excellence through technical leadership, knowledge-sharing and mentorship
Instate best-practices observability and monitoring as “first principles” of all our services
Keep extremely sensitive data compartmentalized and secure
Perform other related duties as assigned
How You Will Do Your Work
As a Senior Software Engineer, how results are achieved is paramount for your success and ultimately result in our success as an organization. In this role, your foundational knowledge, skills, abilities and personal attributes are anchored in the following competencies:
Good judgment - the exercise of critical thinking, analyzing and assessing problems and implications, identifying patterns, making connections of underlying issues, understanding risks and developing mitigation strategies, and taking ownership of the outcome.
Resourcefulness - taking a can-do approach, even in the face of obstacles and constraints by assessing what’s in front of you and effectively and efficiently optimizing what you have, whether it's