Software Engineer, Backend - Unified Gateway

DoorDash Canada•Toronto, ON

2d•CA$120,000 - CA$150,000

About The Position

As a member of the Unified Gateway team, you'll build and maintain the API Gateway platform that sits at the front door of DoorDash's traffic — an HTTP-to-gRPC reverse proxy that accepts REST/JSON requests, translates them into Protocol Buffer messages, calls downstream gRPC services, and translates the responses back to clients. The platform empowers product engineers to declaratively define, test, deploy, and operate their API endpoints without standing up and managing their own edge services. It centrally handles authentication, authorization, request and response mapping, header propagation, encryption, and resilience, and powers experiences across DoorDash, Wolt, and Deliveroo spanning iOS, Android, and Web. By providing this robust platform, we deliver significant improvements in: Velocity: Product engineers can iterate faster and deliver features more quickly. Scalability: The platform is designed to handle increasing demand and traffic seamlessly. Reliability: A safe programming model, centralized management, and standardized practices enhance system stability and reduce errors. Cost Efficiency: Consolidating resources and streamlining processes optimizes operational costs across DoorDash.

Requirements

2+ years of experience in backend, infrastructure, or platform engineering.
Experience with gRPC, REST APIs, Protocol Buffers, and service-to-service communication patterns.
Deep knowledge of best practices in Kotlin (or another JVM language) for building high-scale, resilient systems; familiarity with asynchronous/reactive frameworks such as Vert.x is a plus.
Experience working on high-throughput, mission-critical production systems.
A strong understanding of distributed systems concepts, including consistency, fault tolerance, load balancing, and resilience patterns.
Comfortable with API gateway and proxy concerns — authentication and authorization, request routing, and schema/contract management (e.g., OpenAPI).
Value solving problems at the platform level, building abstractions that make life easier for hundreds of engineers.
Proficiency in using AI coding tools (e.g., Claude Code, Codex, Cursor) in the full software development lifecycle, including designing, generating code, testing, monitoring and releasing software.

Responsibilities

Design and build robust, scalable systems with engineering excellence and long-term maintainability in mind.
Improve performance, reliability, scalability, and security across the gateway and its request-processing pipeline.
Drive best practices in API management, service discovery, load balancing, and fault tolerance.
Champion adoption of the Unified Gateway platform across product teams.
Troubleshoot and resolve complex issues in our high-throughput production environment.
Evaluate and integrate new technologies to enhance the platform's capabilities.
Leverage the latest AI-assisted development tools and best practices.