Volunteer Backend Developer Internship Jobs in California

Who we are 

In the past, to be a successful restaurateur, you simply had to have a passion for food and a passion for people - but to succeed as a digital restaurateur you also need to have a passion for technology. We believe in the joy of serving others, and that's why we created Otter - to help restaurateurs succeed in online food delivery. Restaurants around the world, both large and small, including Chick-fil-A, Ben & Jerry's, KFC, and Eataly trust our software to power their delivery business. We increase sales, reduce order issues, and decrease delivery headaches.

What you'll do

At Otter POS, we build the backend that keeps restaurant point-of-sale running: orders, payments, menus, and device state across Android tablets in the kitchen and at the counter. Those services have to stay consistent when WiFi drops mid-service.

As a backend engineer on this team, you will design and scale the services behind order orchestration, payment flows, offline-first sync, and multi-device coordination. We want product-minded or systems-focused backend engineers. You do not need prior POS experience. If you like distributed systems, careful API design, and reliability work under real restaurant conditions, you will fit here.

Core responsibilities

• Design, build, and maintain Java backend services for order lifecycle, payments, device sync, and restaurant workflows.
• Design and optimize APIs and event-driven systems so POS devices, kitchen displays, and cloud services stay consistent with low latency.
• Build systems that keep working offline and sync across multiple devices in a facility.
• Work with Android engineers, product managers, and other teams to ship systems used in live restaurants.
• Keep code quality high through testing, code reviews, observability, and owning what you ship in production.

What we're looking for

• Bachelor's degree in Computer Science or equivalent experience is required.
• 3+ years of professional software engineering experience.
• Deep understanding of backend system design, APIs, data stores, microservices, concurrency, and distributed systems.
• Our stack heavily utilizes Java and Kotlin, but we care more about your engineering fundamentals than the specific languages you've used.
• Experience with relational and/or NoSQL databases (e.g., PostgreSQL, CockroachDB, Redis).
• Experience with cloud platforms like AWS, Google Cloud, or Azure.

Preferred Qualifications

• Experience with event streaming or stream processing (e.g., Kafka, Flink).
• Experience building systems that handle ordering states, payment flows, or multi-device coordination.
• Familiarity with offline-first architectures, sync protocols, or conflict resolution (CRDTs a plus).
• Comfort working with mobile and client engineers, including how backend choices affect reliability on the device.
• Interest in building systems that restaurant operators and staff use every day.

Why join us 

• Demand for online food delivery is growing really fast! In the last 5 years, just in the US, the overall market has expanded 10X from $10B to $100B, and could expand to $500bn- $1T by 2030.
• Changing the restaurant industry: You'll be part of a team that helps restaurants succeed in online food delivery. 
• Collaborative environment: You will receive support and guidance from experienced colleagues and managers, helping you to learn, grow and achieve your goals, and you'll work closely with other teams to ensure our customer's success.

What else you need to know 

This role is based in our Los Angeles office location. As a company driven by innovation and continuous change, close collaboration is essential. We're constantly reimagining our industry, creating new products, and refining our processes, and we do our best work together. That's why all of our office-based teams work onsite, five days a week. 

The base salary range for this role is $167,000 - $230,000 per year.

Actual compensation will be determined on an individual basis and may vary depending on experience, skills, and qualifications.

Base salary is just one part of your total rewards package. You may also be eligible for equity awards and an annual performance-based bonus.

Benefits Summary (USA Full-Time Exempt Employees):

• Medical, dental, and vision insurance (multiple plans, incl. HSA options).
• Company-paid life and disability insurance (short- and long-term).
• Voluntary insurance: accident, critical illness, hospital indemnity.
• Optional supplemental life insurance for self, spouse, and children.
• Pet insurance discount.
• 401(k).
• Health Savings Account (HSA)
• Flexible Spending Accounts (Healthcare, Dependent Care, Commuter)
• Time Off policies:
• Discretionary vacation days
• 8 paid holidays per year
• Paid sick time
• Paid Bereavement leave
• Paid Parental Leave

Benefits are subject to change at the company's discretion.
Atoms accepts applications on an ongoing basis.

Ready to join us as we serve those who serve others? 

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