Senior Software Development Engineer - Core Team (Hybrid @ Bellevue, WA or Florida)
OfferUp
About the role:
As a Senior Backend Engineer on the Core team, you will play a critical role in maintaining and evolving OfferUp's client engineering platform and app ecosystem, as well as leading efforts to build systems that detect and prevent fraudulent behavior in our marketplace. You will ensure app stability, performance, and developer efficiency by tackling complex technical challenges, collaborating across teams, and driving innovation. The systems you build will help maintain our community guidelines and support our partner team's growth and business strategies, focusing on key issues such as account takeovers, Phishing, Payment chargebacks, and Prohibited Items. As a backend developer, you will build highly scalable systems to detect and prevent fraud and continuously improve our engineering/operational excellence.
What You’ll Do
- Work collaboratively with cross-functional teams (risk analysts, data science, and operations) to design and implement new features
- Analyze the latest attacker techniques and apply solutions to detect them holistically and stop them proactively
- Drive engineering and operational excellence across the Core engineering team
- Collaborate with OfferUp-wide engineering teams to improve processes, surface common pain points, develop solutions, and evangelize best practices
- Identify when to replace and when to rebuild legacy systems
- Participate in reasonable on-call rotations with the rest of the team
- Support, mentor, and help other engineers on the team
- Develop highly scalable classifiers and tools leveraging machine learning, data regression, and rules-based models
- Ensure app stability by identifying and resolving crashes, freezes, and network errors across both React Native and native layers
- Develop reusable tools and frameworks to streamline development and improve the developer experience
- Mentor and guide junior engineers, fostering best practices for frontend and native development
You’ll thrive in this role if you have:
- 5+ years of professional software engineering experience, of which at least 3 were devoted to web services
- 2+ years of experience in real-time messaging systems
- Experience performing data analysis and translating the results into business recommendations
- Experience in working with data-driven applications at scale
- Strong coding skills in Java, Python, Scala, Golang, or any other modern programming language, coupled with strong knowledge in object-oriented design and microservices architecture
- BS or MS in Computer Science, Computer/Software Engineering, Information Systems/Technology, Information Science, or a related discipline
Helpful, but not required:
- Proficiency in native development languages: Swift/Objective-C (iOS) and Kotlin/Java (Android)
- Experience with Agile development methodologies
- Experience with load balancing and handling massive data traffic
- Experience writing code in Python and Java
- Experience with cloud infrastructure AWS
Compensation Range: $180,000 - $205,000
About OfferUp:
OfferUp is dedicated to creating the simplest and most trusted way for people to buy, sell, and connect in their local communities. One of the top local marketplace apps for local buyers and sellers in the U.S., OfferUp makes it easy for people to discover more of what they need—from great deals and secondhand goods to jobs, services, home rentals, and more—right in their own communities. Our trusted platform empowers millions to connect, thrive, and move life forward.
Available on iOS and Android, OfferUp has consistently ranked among the top shopping apps. Founded in 2011 and based in Bellevue, WA, OfferUp serves local markets nationwide and was used by more than 1 in 6 adults in the U.S. in 2024. OfferUp is backed by leading investors, including Andreessen Horowitz, Warburg Pincus, GGV Capital, T. Rowe Price, and Coatue Management. https://about.offerup.com
More About OfferUp At a Glance
- Top 10 Shopping app in the App Store and Google Play Store for three years
- 15%+ of adults in several major markets use OfferUp every month (LA, Miami, Phoenix, Seattle, Las Vegas, Riverside, Orlando)
- OfferUp works directly with nearly 2000 US law enforcement agencies to build trust in local communities
OfferUp is unleashing the power of local, and we’ve built a dynamic team to do it. To learn more about working at OfferUp, check out https://about.offerup.com/people
OfferUp provides equal employment opportunities (EEO) to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability, or genetics. In addition to federal law requirements, OfferUp complies with applicable state and local laws governing nondiscrimination in employment in every location in which the company has facilities. This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, transfer, leaves of absence, compensation, and training.
OfferUp expressly prohibits any form of workplace harassment based on race, color, religion, gender, sexual orientation, gender identity or expression, national origin, age, genetic information, disability, or veteran status. Improper interference with the ability of OfferUp’s employees to perform their job duties may result in discipline up to and including discharge.