About Poshmark
Poshmark is a leading fashion resale marketplace powered by a vibrant, highly engaged community of buyers and sellers and real-time social experiences. Designed to make online selling fun, more social and easier than ever, Poshmark empowers its sellers to turn their closet into a thriving business and share their style with the world. Since its founding in 2011, Poshmark has grown its community to over 130 million users and generated over $10 billion in GMV, helping sellers realize billions in earnings, delighting buyers with deals and one-of-a-kind items, and building a more sustainable future for fashion. For more information, please visit www.poshmark.com, and for company news, visit newsroom.poshmark.com.We are seeking an experienced Senior Software Engineer I to join our Core Platform team and contribute to the continued scalability and innovation of our backend systems. As a key technical contributor, you will play a critical role in building and optimizing the cloud-native infrastructure and services that power our high-traffic marketplace. The Poshmark community creates a new listing every 2 seconds and generates millions of likes, comments, and shares every single day — this is your opportunity to impact the core of that experience.
Responsibilities
- Lead the design, development, and deployment of scalable backend services and distributed systems.
- Help evolve our application and service delivery platform, leveraging cloud-native architectures, NoSQL solutions, queueing technologies, and search infrastructure.
- Architect and implement new product features using a data-driven, iterative approach with measurable impact.
- Drive performance tuning and system improvements to ensure reliability, scalability, and maintainability of key components.
- Collaborate with cross-functional teams — including Product, Design, DevOps, and QA — to deliver high-quality software aligned with business goals.
- Actively participate in code reviews, technical discussions, and mentoring of junior engineers.
- Identify and lead refactoring and technical debt reduction efforts to improve developer velocity and system health.
6-Month Accomplishments
- Ramp up quickly on Poshmark’s codebase, cloud architecture, and development workflows.
- Take ownership of key components or services and contribute high-quality, well-tested code to production.
- Serve as a go-to technical resource within your immediate team.
- Drive cross-team collaboration to deliver features and improvements efficiently and effectively.
12+ Month Accomplishments:
- Lead the technical execution of complex initiatives with multiple dependencies and stakeholders.
- Influence architectural decisions and contribute to long-term platform and service strategy.
- Drive engineering excellence through best practices, tooling, and process improvements.
- Provide mentorship and technical leadership across the backend engineering team.
Requirements
- 4+ years of professional backend software engineering experience, including designing and scaling distributed systems.
- Strong foundation in computer science, including data structures, algorithms, and software design principles.
- Proficiency with backend programming languages such as Ruby and/or Java.
- Experience working with technologies like MongoDB, ElasticSearch, RabbitMQ, and Redis.
- Strong understanding of RESTful API design and implementation.
- Experience with scalability, performance optimization, and systems-level problem solving.
- Familiarity with microservices architecture and cloud platforms (e.g., AWS, GCP) is a plus.
- Bachelor's or Master’s degree in Computer Science or a related field.
- Strong communication skills and a user-centric, quality-first mindset.
