Senior Software Engineer, Core Services (Backend)

Senior Software Engineer - Core Services

Employment Type: [Not Specified] Location Type: Remote (US, UK, Singapore) / Hybrid / Office (San Mateo, CA)

Position Overview

OneSignal is seeking a Senior Software Engineer to join our Core Services team. This role is instrumental in designing, developing, and operating the cross-cutting horizontal services that form the backbone of our high-performance customer engagement platform. You will work with cutting-edge technologies like Rust, gRPC, Kafka, and Scylla to build systems that handle billions of messages daily and operate on hundreds of thousands of events per second while maintaining durability and reliability. As a Senior Software Engineer, you will have the autonomy to own significant projects, directly impact platform performance and features, and contribute to shaping how businesses engage with their users.

About OneSignal

OneSignal is a leading omnichannel customer engagement solution, empowering over a million businesses to personalize customer journeys across mobile and web push notifications, in-app messaging, SMS, and email. We democratize engagement, enabling businesses to connect with their users by delivering billions of messages daily. We are a Series C, venture-backed company with a strong emphasis on healthy work-life balance, kindness, ownership, and personal growth. We offer remote work as the default option in many US states, the UK, and Singapore, with plans for future expansion.

About The Team

The Core Services team is responsible for the high-performance, low-cost infrastructure that powers OneSignal's massive scale. We leverage modern data stores and write scale-sensitive components in languages like Rust. Our work includes the delivery pipeline, gRPC services, and Kafka, supporting systems that process hundreds of thousands of events per second. You will work with a tech stack including Rust, gRPC, Redis, Kafka, Scylla, ClickHouse, Pulsar, PostgreSQL, and occasionally Golang and Ruby.

Responsibilities

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

Requirements

• At least 6 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++, Java, or Golang.
• Ability to reason about how systems operate.

Application Instructions

[Not Specified]