# Senior Software Engineer II, Backend
**Company:** [Poshmark](https://scaleengineer.com/companies/poshmark)
Join Poshmark's Core Platform team as a Senior Software Engineer II to design and operate scalable backend systems powering a 165-million-member fashion marketplace. This role demands 7+ years of production backend engineering expertise, with independent ownership of complex distributed systems, API development, and mentorship responsibilities. You'll solve high-impact engineering challenges across database optimization, service scalability, and operational reliability while collaborating with product, infrastructure, and cross-functional teams to drive marketplace excellence.
**Role:** Backend Engineer
**Seniority:** Senior
**Locations:** US California (Redwood City) - Office
**Salary:** 180000–240000 USD
[Apply](https://jobs.ashbyhq.com/poshmark/ab4be205-bf24-4bba-9205-b0f9722d9606)
Canonical: https://scaleengineer.com/jobs/poshmark/senior-software-engineer-ii-backend
---
## Responsibilities

- Design and Operate Scalable Backend Services: Architect, develop, test, and deploy production-grade backend services that support Poshmark's high-traffic marketplace platform. Ensure systems meet requirements for scalability, performance, and reliability while handling millions of concurrent users and transactions across the platform.
- Own Complex Technical Initiatives End-to-End: Take full ownership of complex backend features and services from technical requirements and design through production deployment and ongoing operational support. Make independent decisions on implementation approaches while evaluating trade-offs across scalability, performance, reliability, security, and operational considerations.
- Translate Product Requirements into Engineering Solutions: Collaborate with product managers to understand marketplace needs and translate them into reliable, maintainable, and extensible software solutions. Develop APIs, data models, asynchronous workflows, and integrations that serve both internal systems and external consumers.
- Troubleshoot and Resolve Production Issues: Diagnose complex production issues through root-cause analysis, implement sustainable fixes, and improve system observability and monitoring. Participate in on-call rotations and ensure rapid incident response with minimal customer impact to the marketplace.
- Enhance System Reliability and Observability: Improve system observability, monitoring, performance, fault tolerance, and operational readiness. Implement monitoring strategies, automated alerts, and performance optimization techniques to ensure marketplace stability during peak traffic periods.
- Lead Technical Design and Code Review Process: Participate actively in technical design reviews, provide constructive feedback during code reviews, and help establish engineering best practices. Contribute to architectural discussions that shape the long-term direction of backend systems.
- Collaborate Across Teams: Work effectively with Product, QA, Infrastructure, and adjacent engineering teams to manage cross-functional dependencies and deliver high-quality solutions. Communicate technical decisions clearly to both technical and non-technical stakeholders.
- Mentor Junior Engineers: Guide junior engineers, interns, and new team members through design discussions, code reviews, and knowledge sharing. Support their technical development and help them understand production systems, debugging techniques, and engineering best practices.
- Improve Development Practices and Tooling: Contribute to improving development processes, engineering practices, testing frameworks, deployment automation, and team workflows. Share technical knowledge and lessons learned to strengthen overall team capabilities.

## Requirements

### education

- {"name":"Bachelor's or Master's Degree in Computer Science","description":"Bachelor's or Master's degree in Computer Science, Engineering, or a related technical discipline, or equivalent hands-on professional engineering experience demonstrating deep systems knowledge."}

### technical

- {"name":"Backend Programming Languages","description":"Proficiency in at least one backend programming language such as Ruby, JRuby, Java, or comparable languages (e.g., Python, Go, Scala). Deep understanding of language idioms, performance characteristics, and ecosystem tools."}
- {"name":"Database Design and Data Modeling","description":"Experience designing schemas, optimizing queries, and working with relational databases. Understanding of indexing strategies, query optimization, database scaling patterns, and data consistency models including ACID and eventual consistency trade-offs."}
- {"name":"Caching and Search Technologies","description":"Hands-on experience with caching layers (Redis, Memcached), search technologies (Elasticsearch), and data retrieval optimization. Understanding of cache invalidation strategies, consistency patterns, and performance implications."}
- {"name":"Message Queues and Async Processing","description":"Experience with messaging systems such as RabbitMQ, Kafka, or similar platforms for building event-driven architectures. Understanding of message delivery guarantees, processing semantics, and handling failure scenarios."}
- {"name":"Monitoring, Observability, and Alerting","description":"Understanding of monitoring architecture, observability best practices, structured logging, distributed tracing, and alerting systems. Experience setting up meaningful metrics and alerts for production systems."}
- {"name":"Deployment and DevOps Practices","description":"Experience with automated testing, continuous integration, deployment pipelines, infrastructure-as-code, and operational readiness processes. Familiarity with containerization and orchestration concepts."}
- {"name":"Computer Science Fundamentals","description":"Strong foundation in computer science fundamentals including data structures (lists, trees, graphs, hash tables), algorithms (sorting, searching, dynamic programming), object-oriented design principles, and SOLID design patterns."}
- {"name":"Security Best Practices","description":"Understanding of backend security considerations including authentication, authorization, secure communication, input validation, and common vulnerability prevention. Experience implementing security measures in production systems."}

### experience

- {"name":"7+ Years Production Backend Engineering","description":"7 or more years of professional software engineering experience specifically building, deploying, and operating production backend systems at scale. Should demonstrate progressive ownership and increasing impact on critical infrastructure."}
- {"name":"Distributed Systems Experience","description":"Hands-on experience working with distributed systems, including understanding of scalability patterns, reliability mechanisms, performance optimization, and consistency trade-offs in high-traffic environments."}
- {"name":"API and Backend Service Development","description":"Proven track record designing, developing, maintaining, and scaling APIs and backend services. Experience with request-response patterns, asynchronous processing, rate limiting, versioning, and API deprecation strategies."}
- {"name":"Production Debugging and Incident Response","description":"Strong debugging and problem-solving skills with hands-on experience diagnosing complex issues in production environments. Experience with performance profiling, memory analysis, and root-cause analysis of system failures."}
- {"name":"Code Quality and Testing Practices","description":"Demonstrated ability to write clean, maintainable, well-tested, and well-documented production code. Experience establishing and maintaining testing standards including unit testing, integration testing, and automated testing frameworks."}

## Skills

### required

- {"name":"Distributed Systems Design","description":"Ability to design, build, and operate systems that scale horizontally across multiple servers and data centers. Understanding of consistency models, replication, partitioning, and handling network failures."}
- {"name":"Independent Technical Ownership","description":"Proven ability to independently drive complex technical projects from conception through production, including requirement analysis, design decisions, implementation, testing, and operational support."}
- {"name":"Production System Reliability","description":"Experience ensuring high availability and reliability of production systems. Ability to design for fault tolerance, implement graceful degradation, and maintain SLAs in mission-critical environments."}
- {"name":"Cross-Functional Collaboration","description":"Strong ability to collaborate effectively with product managers, QA engineers, infrastructure teams, and other backend engineers. Excellent communication skills for explaining technical trade-offs and decisions to diverse audiences."}
- {"name":"Technical Problem Solving","description":"Exceptional debugging and troubleshooting skills with ability to analyze complex system behavior, identify root causes, and implement effective solutions. Experience with performance optimization and capacity planning."}
- {"name":"Code Quality and Maintainability","description":"Commitment to writing clean, well-structured, thoroughly tested code. Experience with code review processes, refactoring, technical documentation, and establishing engineering standards."}
- {"name":"Mentorship and Knowledge Sharing","description":"Ability to guide junior engineers through design discussions, code reviews, and problem-solving. Willingness to share technical knowledge and help team members grow their engineering capabilities."}

### preferred

- {"name":"Cloud Platform Experience","description":"Experience with Amazon Web Services (AWS), Google Cloud Platform (GCP), Azure, or similar cloud computing platforms. Familiarity with cloud-native patterns, managed services, and cloud infrastructure best practices."}
- {"name":"Ruby or JRuby Expertise","description":"Specific experience with Ruby or JRuby programming language and Rails framework. Understanding of Ruby idioms, metaprogramming concepts, and performance characteristics in high-traffic applications."}
- {"name":"Microservices Architecture","description":"Experience building and operating service-oriented or microservices-based architectures. Understanding of service boundaries, inter-service communication, distributed transactions, and operational complexity trade-offs."}
- {"name":"High-Traffic Platform Experience","description":"Background building systems for high-traffic consumer or marketplace platforms handling millions of concurrent users. Experience with scaling challenges, traffic spikes, and real-time data processing at scale."}
- {"name":"Performance Optimization","description":"Track record of identifying and implementing performance optimizations in backend systems. Experience with profiling tools, benchmarking methodologies, and capacity planning for handling growth."}
- {"name":"Large-Scale Messaging Systems","description":"Experience designing and operating large-scale messaging systems for email delivery, push notifications, or similar high-volume communication platforms. Understanding of throughput, latency, and reliability trade-offs."}
- {"name":"Linux System Administration","description":"Practical experience with Linux systems administration, shell scripting, system troubleshooting, and server operations. Comfort working in Unix-like environments and understanding system-level performance tuning."}

## Tech stack

### tools

- {"name":"Elasticsearch","description":"Search and analytics engine used for marketplace search functionality and log analysis. Experience with indexing strategies, query optimization, and cluster management is valuable."}
- {"name":"RabbitMQ","description":"Message broker for asynchronous processing, event handling, and service-to-service communication. Understanding of queue patterns, message delivery guarantees, and scaling is important."}
- {"name":"Amazon Web Services (AWS)","description":"Cloud infrastructure platform hosting Poshmark's systems. Experience with EC2, S3, RDS, Lambda, SQS, SNS, and other AWS services is valuable for operational work."}
- {"name":"Docker","description":"Containerization technology for packaging, deploying, and running backend services. Understanding of Docker concepts, image management, and container orchestration is beneficial."}
- {"name":"Git","description":"Version control system for source code management. Proficiency with Git workflows, branching strategies, and collaboration practices is essential."}

### others

- {"name":"Distributed Tracing","description":"Tools and techniques for tracing requests across distributed systems. Experience with systems like Jaeger or Zipkin helps understand system behavior and debug complex issues."}
- {"name":"Metrics and Monitoring","description":"Time-series databases and monitoring platforms like Prometheus, Datadog, or similar tools for collecting and analyzing system metrics. Critical for production observability."}
- {"name":"Linux Command Line","description":"Deep familiarity with Unix/Linux command-line tools, shell scripting, and system diagnostics. Essential for troubleshooting production issues and system administration tasks."}
- {"name":"API Design Patterns","description":"Knowledge of RESTful API design, GraphQL, gRPC, and other API architectural patterns. Understanding of versioning strategies, deprecation, and API evolution."}

### databases

- {"name":"MongoDB","description":"NoSQL document database used for flexible data modeling and horizontal scalability. Experience with MongoDB query optimization, indexing, and replica sets is valuable."}
- {"name":"PostgreSQL","description":"Relational database system used for transactional data and complex queries. Proficiency in query optimization, indexing strategies, and scaling patterns is important."}
- {"name":"Redis","description":"In-memory data structure store used for caching, session management, and real-time features. Understanding of Redis data structures, key expiration, and cache patterns is beneficial."}

### languages

- {"name":"Ruby","description":"Primary backend language for Poshmark's platform, used for building API endpoints, business logic, and service implementations. Strong Ruby proficiency is valuable for rapid onboarding."}
- {"name":"Java","description":"Alternative backend language for performance-critical services and systems requiring strong type safety. Useful for building distributed systems and handling high-throughput processing."}
- {"name":"SQL","description":"Essential for database query optimization, schema design, and data manipulation. Deep SQL knowledge required for troubleshooting database performance issues at scale."}

### frameworks

- {"name":"Rails","description":"Ruby on Rails framework commonly used for building web applications and APIs. Understanding of Rails patterns, middleware, and performance optimization techniques is beneficial."}

## Benefits

### benefits

- {"name":"Professional Development and Learning","description":"Access to continuous learning opportunities, technical training programs, conference attendance budgets, and mentorship from experienced engineers. Poshmark invests in engineer growth and career development."}
- {"name":"Comprehensive Health Insurance","description":"Competitive health insurance coverage including medical, dental, and vision plans. Coverage extends to employees and eligible dependents with company contribution toward premiums."}
- {"name":"Retirement Planning","description":"401(k) retirement plan with company matching contributions to help secure long-term financial future. Access to financial planning resources and retirement guidance."}
- {"name":"Flexible Time Off","description":"Generous paid time off policies supporting work-life balance. Flexible vacation days, sick leave, and personal days to manage personal and professional responsibilities."}
- {"name":"Stock Options and Equity","description":"Equity participation through stock options aligning your success with company growth. Poshmark offers meaningful equity packages to engineering staff enabling wealth building."}
- {"name":"Remote Work Flexibility","description":"Flexible work arrangements supporting distributed work and work-life balance. Options for remote, hybrid, or office-based arrangements depending on team and role needs."}
- {"name":"Engineering-Focused Culture","description":"Engineering-first organizational culture that values technical excellence, thoughtful design, and continuous improvement. Strong emphasis on code quality, system reliability, and technical innovation."}
- {"name":"Mission-Driven Work","description":"Opportunity to impact a large, engaged community of 165 million users. Build systems that enable sustainable fashion commerce and meaningful human connection through a thriving marketplace."}

## Compensation

- **max:** 0
- **min:** 0
- **currency:** 
- **stockOptions:** false

## Interview process

### steps

## Full description
## About Poshmark

  
**Poshmark is the leading fashion marketplace where style comes alive through discovery, self-expression, and human connection.** Powered by a vibrant community of 165 million members, Poshmark brings real people and taste to shopping through a social experience shaped by shared discovery. Buying and selling fashion feels simple, joyful, and personal, while every item tells its own story. Poshmark empowers sellers to grow meaningful businesses, keeps fashion in circulation longer, and gives shoppers access to unique and trusted finds, from everyday pieces to one-of-a-kind vintage and luxury.

Poshmark is looking for a Senior Software Engineer II to join our Core Platform team and build reliable, scalable, and high-performance backend systems that power our marketplace.

In this role, you will independently own complex backend features and services from technical design through production. You will solve challenging engineering problems across distributed systems, make thoughtful technical trade-offs, and work closely with Product, QA, Infrastructure, and other engineering teams.

You will also contribute to technical design discussions, mentor junior engineers, and help improve the reliability, maintainability, and operational excellence of the systems owned by the team.

## **Responsibilities**

* Design, develop, test, deploy, and operate scalable backend services that support Poshmark’s marketplace.
* Independently own complex, well-defined technical initiatives from requirements and design through production rollout and ongoing support.
* Translate product and technical requirements into reliable, maintainable, and extensible software solutions.
* Make sound design and implementation decisions by evaluating scalability, performance, reliability, security, and operational trade-offs.
* Develop and enhance APIs, data models, asynchronous workflows, and integrations across distributed systems.
* Troubleshoot complex production issues, perform root-cause analysis, and implement sustainable fixes.
* Improve system observability, monitoring, performance, fault tolerance, and operational readiness.
* Participate actively in technical design reviews and provide constructive feedback through code reviews.
* Collaborate with Product, QA, Infrastructure, and adjacent engineering teams to manage dependencies and deliver high-quality solutions.
* Contribute to improving development processes, engineering practices, tooling, and team workflows.
* Mentor junior engineers and support their technical development through design discussions, code reviews, and knowledge sharing.
* Participate in production support and on-call responsibilities as required by the team.

## **What You Will Accomplish in the First 6 Months**

* Develop a strong working knowledge of Poshmark’s architecture, technology stack, development practices, and production environment.
* Independently deliver a complex backend feature or service from technical design through production.
* Take ownership of the quality, reliability, and operational health of assigned services or components.
* Contribute meaningfully to technical design discussions and code reviews.
* Build effective working relationships with Product, QA, Infrastructure, and adjacent engineering teams.
* Identify and implement improvements to the performance, reliability, maintainability, or developer experience of an owned system.

## **What You Will Accomplish in 12+ Months**

* Consistently lead the end-to-end delivery of complex backend initiatives within the team’s scope.
* Become a trusted technical owner for one or more important services or components.
* Drive measurable improvements in system scalability, performance, reliability, or operational efficiency.
* Help scope technical work, identify dependencies, and manage delivery risks for team initiatives.
* Contribute recommendations to the team’s architectural direction and technical roadmap.
* Strengthen engineering practices through design reviews, code quality improvements, documentation, testing, and operational standards.
* Mentor junior engineers, interns, and new team members and help them become productive within the organization.
* Share technical knowledge and lessons learned across the team.

## **Requirements**

* Bachelor’s or Master’s degree in Computer Science, Engineering, or a related technical discipline, or equivalent practical experience.
* 7+ years of professional software engineering experience, including experience building and operating production backend systems.
* Strong foundation in computer science fundamentals, including data structures, algorithms, object-oriented design, and software design principles.
* Proficiency in at least one backend programming language such as Ruby, JRuby, Java, or a comparable language.
* Experience designing, developing, and maintaining APIs and backend services.
* Experience working with distributed systems and understanding their scalability, reliability, and performance considerations.
* Experience with databases, data modelling, caching, search technologies, or messaging systems.
* Experience writing clean, maintainable, well-tested, and well-documented production code.
* Strong debugging and problem-solving skills, including experience diagnosing issues in production environments.
* Understanding of monitoring, observability, automated testing, deployment, and operational readiness.
* Ability to independently drive technical work while collaborating effectively with engineers and cross-functional partners.
* Strong written and verbal communication skills, with the ability to explain technical decisions and trade-offs clearly.
* Demonstrated commitment to product quality, customer experience, and continuous improvement.

## **Preferred Qualifications**

* Experience with Amazon Web Services or another major cloud computing platform.
* Experience with one or more of the following technologies: Ruby, JRuby, Java, MongoDB, Elasticsearch, RabbitMQ, and Linux.
* Experience building cloud-native services for a high-traffic consumer or marketplace platform.
* Experience with service-oriented or microservices-based architectures.
* Experience with performance optimization, capacity planning, and production incident response.
* Experience with email, push notification, or other large-scale messaging technologies.
* Previous experience mentoring junior engineers, interns, or new team members.