Staff Backend Engineer (Streaming & AI Infrastructure)

Company Introduction

We exist to wow our customers. We know we're doing the right thing when we hear our customers say, “How did we ever live without Coupang?” Born out of an obsession to make shopping, eating, and living easier than ever, we're collectively disrupting the multi-billion-dollar e-commerce industry from the ground up. We are one of the fastest-growing e-commerce companies that established an unparalleled reputation for being a dominant and reliable force in South Korean commerce.

We are proud to have the best of both worlds — a startup culture with the resources of a large global public company. This fuels us to continue our growth and launch new services at the speed we have been since our inception. We are all entrepreneurs surrounded by opportunities to drive new initiatives and innovations. At our core, we are bold and ambitious people that like to get our hands dirty and make a hands-on impact. At Coupang, you will see yourself, your colleagues, your team, and the company grow every day.

Role Overview

As part of our Application Infrastructure org, this is a team building Coupang’s next-generation Real-Time Streaming & AI Platform that powers the end customer website and mobile apps.

We are looking for a visionary Staff Software Engineer to lead the architectural design of a platform capable of processing over 100k+ events per second with sub-second, end-to-end latency. This system will serve as the central nervous system for Coupang, enabling real-time product and customer data and instant personalization. You will build a system that doesn't just meet industry standards but sets them, ensuring 5-6 nines availability while leveraging AI to optimize data flows and automate complex system behaviors.

Responsibilities

• Architect for Velocity: Lead the end-to-end design of a distributed streaming engine. You will Build the Best Team and Help Them Grow by setting the gold standard for high-throughput, low-latency architectural integrity.
• Define Extreme Performance: Design for "5-6 nines" (99.9999% availability) at a throughput of 100k+ events/sec. You will Dive Deep into JVM tuning, memory management, and network I/O to ensure sub-second latency across global clusters.
• AI-Driven Streaming: Integrate AI/ML models directly into the stream processing path. Implement predictive scaling and intelligent load balancing to ensure we Wow the Customer through seamless, real-time platform responsiveness.
• Solve Hard Problems: Address challenges related to distributed consistency, at times, exactly-once processing guarantees, and backpressure management. You must Be Data-Driven to validate architectural decisions against massive, bursty traffic patterns.
• Lead with Influence: As a Staff Engineer, you will Influence without Authority, collaborating with domain teams to migrate legacy batch processes to real-time streaming architectures.

Basic Qualifications

• Bachelor's degree in Computer Science, Electrical Engineering, Math, or a closely related field.
• 6+ years of experience in backend software development.
• Expert-level experience in Cassandra, TiDB, or DynamoDB
• Expert-level proficiency in Java and the Spring Framework.
• Demonstrated experience in building and maintaining highly available, distributed systems in cloud environments (AWS).
• Experience with high-volume messaging systems (e.g., Kafka, SQS).

Preferred Qualifications 

• Extensive Experience: 10+ years of professional software development experience building backend infrastructure that supports global-scale, real-time traffic.
• Performance Expert: Proven track record of optimizing JVM applications for ultra-low latency (<100ms p99s) and high concurrency.
• AI Integration: Experience or a strong architectural vision for using AI/ML to automate system-level functionality, such as real-time anomaly detection in data streams.
• Distributed Systems Expert: Deep understanding of the CAP theorem, consensus algorithms, and building fault-tolerant systems from the ground up.
• Observability Expert: Expertise in building highly observable systems using distributed tracing and advanced telemetry to proactively identify bottlenecks in the streaming pipeline.

Recruitment Process and Others

• Recruitment Process 

1. Application Review - Phone Interview - Onsite (or Virtual Onsite) Interview – Offer 
2. The exact nature of the recruitment process may vary according to the specific job and may be changed due to scheduling or other circumstances. 
3. Interview schedules and the results will be informed to the applicant via the e-mail address submitted at the application stage. 

• Things to Consider 

1. This job posting may be closed prior to the stated end date for application if all openings are filled.    
2. Coupang has the right to rescind an offer of employment if a candidate is found to have submitted false information as part of the application process.    
3. Coupang does not discriminate against disabled applicants or those with veteran status. We are proud to offer equal opportunities for all applicants. 

• Privacy Notice 

1. Your personal information will be collected and managed by Coupang as stated in the Application Privacy Notice located HERE. 

• Document Return Policy 

1. This notification is given pursuant to Article 11 (6) of the Fair Hiring Procedure Act.  
2. A job applicant, who has applied but not been finally selected for a position at Coupang (the “Company”), may request the Company to return his/her hiring documents submitted pursuant to the Fair Hiring Procedure Act.  However, this will not apply where the hiring documents were submitted via the website of the Company or e-mail, or where the job applicant submitted those documents voluntarily without a request from the Company.  In addition, if the hiring documents were destroyed due to a natural disaster or any other reasons not attributable to the Company, such documents will be deemed to have been returned to the job applicant. 
3. A job applicant who wishes to request the return of his/her hiring documents pursuant to the main sentence of paragraph 2 above should fill out a “Request for Return of Hiring Documents” [Annex Form No. 3 in the Enforcement Rule of the Fair Hiring Procedure Act] and submit the request to the Company by email ([email protected]) In such case, within fourteen (14) days from the date of identifying the receipt of the request, the Company will send the hiring documents to the job applicant’s designated address via registered mail.  Please be informed that the job applicant is required to pay the postage on the registered mail. 
4. In preparation for a job applicant’s request for the return of hiring documents pursuant to the main sentence of paragraph 2 above, the Company shall retain the original hiring documents submitted by the job applicant for 180 days from the completion of the recruiting process.  If no request is made until the end of this period, all of his/her hiring documents will be destroyed immediately in accordance with the Personal Information Protection Act. 

Equal Opportunities for All

Coupang is an equal opportunity employer. Our unprecedented success could not be possible without the valuable inputs of our globally diverse team.