Software Engineer III, Rating

Here at Shippo, we are the shipping layer of the internet and we consider ourselves to be one of the core building blocks of e-commerce.
Our mission is to make merchants successful through world class shipping. With our products and solutions, we level the playing field by providing our customers with best-in-class solutions that otherwise wouldn’t be available to them. Through Shippo e-commerce businesses, marketplaces, platforms and a variety of logistics infrastructure providers are able to connect to shipping carriers around the world from one API and dashboard. We provide our customers with the most competitive shipping rates, print labels, automated international documents, shipment tracking, facilitate the returns process and more.
Our Rating API team plays a crucial role in powering Shippo’s core API. The `/shipments` endpoint enables real-time shipping rate calculation across multiple carriers. This team ensures merchants and platforms get fast, accurate, and reliable rate comparisons that drive conversion and customer satisfaction.
How we’ll deliver success:The Rating Team is seeking a Software Engineer III to build and maintain Shippo’s Rating Core APIs and critical carrier integrations (including USPS, UPS, and FedEx), while advancing Shippo’s carrier integration technology.Success in this role means delivering highly performant, low-latency APIs that can calculate millions of shipping rates daily. You’ll design and optimize the systems that ensure merchants, partners, and platforms can seamlessly access accurate rates worldwide. You will work across Golang and Python services. From enhancing our rating orchestrator microservice and rate card ingestion pipeline to extending functionality in our `/shipments` API. The ideal candidate will improve scalability, reliability, and developer experience for one of Shippo’s most essential APIs.

Shipping & Handling Responsibilities

• Design, implement, test, and deploy high-performance backend services that handle millions of requests daily with strong SLAs.
• Develop and maintain scalable microservices in Golang and Python, focusing on rating orchestration and carrier rate ingestion.
• Enhance and support our /shipments API, ensuring performance, accuracy, and low latency for all users.
• Collaborate with cross-functional partners (Product, Infrastructure, and Carrier Integrations) to deliver key API capabilities.
• Continuously improve the CI/CD pipeline for efficient, reliable, and automated deployments.
• Monitor, measure, and improve system health through metrics, logging, and observability tools.
• Participate in code and design reviews, providing thoughtful feedback and mentorship to peers and junior engineers.
• Engage in the team’s on-call rotation, troubleshooting production incidents quickly and effectively.
• Drive technical excellence and contribute to long-term architectural improvements across the rating system.

Do You Tick The Boxes?

• 6+ years of professional software development experience.
• Proficiency in backend programming languages such as Golang, Python, Java, or Ruby, and solid understanding of SQL databases.
• Experience building and scaling high-throughput APIs and distributed systems.
• Strong understanding of microservices architecture, API design, and system performance optimization.
• Experience with RESTful and/or gRPC-based APIs and integrations.
• Proven ability to collaborate cross-functionally and communicate complex technical concepts clearly.
• Strong problem-solving skills and a track record of delivering maintainable, production-grade code.
• Deep understanding of customer needs and passion for customer success.
• Exceptional verbal, written, and interpersonal communication skills. You are adept at communicating relevant information clearly and concisely.
• Demonstrated commitment to craftsmanship, reliability, and continuous improvement.
• Bachelor’s or Master’s degree in Computer Science or equivalent experience.

Bonus

• Prior experience integrating or working with shipping and postal carriers.
• Familiarity with microservices frameworks such as FastAPI, Django, or Flask.
• Experience using Python and/or Golang in production at scale.
• Background in performance tuning, concurrency, data pipelines, or systems optimization.
• Experience with Kafka, SQS, Celery, or similar messaging systems.
• Exposure to DevOps tooling (Docker, Kubernetes, Terraform, CircleCI, GitHub Actions, ArgoCD, New Relic, PagerDuty/Incident.io).
• Knowledge of AWS Cloud Services such as EC2, S3, DynamoDB, Lambda, and CloudFormation.

Sail through the process:Here at Shippo, we celebrate inclusivity and are committed to creating equal access to opportunities for people from all backgrounds, perspectives and geographies. These values define who we are and everything we do. All qualified individuals are encouraged to apply. If you need assistance, or a reasonable accommodation during the application and recruiting process, please contact us at accommodations@goshippo.com
Shippos in the wild:Our people, much like the packages we help ship, are all over the world. This means, through our remote-first program, “Shippos Everywhere”, our roles can be based anywhere in the US with the exception of Delaware, Nevada, Ohio, Oregon, Hawaii, New Mexico and West Virginia and many roles can be based internationally.
For locations outside of the US and Ireland, the employment contracts are powered by Remote.com. What we want to emphasize is that you can be successful at Shippo regardless of location.