Staff Software Engineer, Core Services

OneSignal is the autonomous lifecycle marketing engine for B2C app companies. Marketers can orchestrate the campaigns that onboard, engage, and retain users, increasing LTV and reducing churn. Companies like Zynga, Bitcoin.com, and Philips use OneSignal to drive outcomes with AI that scales with you.

We’re Series C, venture-backed by SignalFire, Rakuten Ventures, Y Combinator, HubSpot, and BAM Elevate. We offer remote work as the default option in the United States in California, Colorado, Florida, Massachusetts, New York, New Jersey, Ohio, Oregon, Pennsylvania, Texas, Utah and Washington. As well as in the UK, Singapore, and Canada - with plans to expand the locations we support in the future. Some roles are hybrid roles and will be listed as such. We have offices in San Francisco and San Mateo in CA, in London, UK, and offer flex seating options for employees to work together in-person in NY and other areas. Hiring in Singapore is done in partnership with a local EOR, and hiring in Canada is done in partnership with Rippling's EOR.

OneSignal has a lot of the great tech startup qualities you'd expect, but we don't stop there. Our massive scale and small team, emphasis on collaboration, and focus on ownership and personal growth make OneSignal a uniquely great place to work.

About The Team:

OneSignal powers billions of messages and HTTP requests every day. We’ve achieved this scale by pairing modern, high-performance data stores with efficient technologies such as Rust, creating reliable systems that maximize performance and resource utilization.

The Core Services team builds and operates the foundational services behind OneSignal’s platform, including our delivery pipeline, gRPC services, Kafka infrastructure, and other systems processing hundreds of thousands of events per second. You’ll work with technologies including Rust, gRPC, Redis, Kafka, Scylla, ClickHouse, Pulsar, PostgreSQL, and occasionally Golang and Ruby.

As OneSignal evolves into a fully autonomous platform, the Core Services team will build and scale the high-stakes services that our products and engineering teams rely on. As a Staff Software Engineer, you’ll lead significant projects and directly shape the reliability, performance, and future of our platform.

What You'll Do

• Collaborate with engineers to architect and implement high-performance services that are durable and reliable
• Participate in code reviews, design reviews, and production on-call rotation
• Work together with the team to resolve production issues and ensure system scalability
• Conduct data analysis, performance monitoring, and system optimization through benchmarking/profiling.
• Work independently to drive experiments and solutions for business needs
• Design synchronous and asynchronous APIs for communicating between services in a large distributed system
• Design schemas for relational and non-relational databases

What You'll Bring:

• 8+ years of experience working as a software engineer
• Experience operating reliable production systems at scale
• Experience writing high-performance code in a compiled language such as Rust, C/C++, or Golang
• Ability to reason about how data flows through distributed systems
• Experience using LLM-powered coding tools, such as Claude, to accelerate development, improve code quality, and enhance engineering workflows.
• Bias towards automating the boring stuff

We value a variety of experiences, and these are not required. It would be a added bonus if you have experience in any of the following:

• Experience with any of Redis, Kafka, Postgres, ClickHouse, gRPC
• Experience profiling applications to improve performance in terms of time/CPU/memory
• Experience debugging issues in distributed systems

The New York and California base salary for this full time position is between $200,000 to $220,000. Your exact starting salary is determined by a number of factors such as your experience, skills, and qualifications. In addition to base salary, we also offer a competitive equity program and comprehensive and inclusive benefits.

Qualities we look for:

• Friendliness & Empathy
• Accountability & Collaboration
• Proactiveness & Urgency
• Growth Mindset & Love of Learning

In keeping with our beliefs and goals, no employee or applicant will face discrimination/harassment based on: race, color, ancestry, national origin, religion, age, gender, marital domestic partner status, sexual orientation, gender identity, disability status, or veteran status. Above and beyond discrimination/harassment based on 'protected categories,' we also strive to prevent other, subtler forms of inappropriate behavior (e.g., stereotyping) from ever gaining a foothold in our office. Whether blatant or hidden, barriers to success have no place in our workplace.

Applicants with disabilities may be entitled to reasonable accommodation under the terms of the Americans with Disabilities Act and certain state or local laws. A reasonable accommodation is a change in the way things are normally done which will ensure an equal employment opportunity without imposing undue hardship on OneSignal. Please inform us if you need assistance completing any forms or to otherwise participate in the application and/or interview process.

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