Whatnot

Senior / Staff Engineer - Platform

Whatnot$130K — $180K *
Information Technology
5 - 7 years of experience
Job Overview by Ladders

Qualifications

  • 5+ years experience in building production systems at scale
  • Strong understanding of security fundamentals and threat modeling
  • Proficient in distributed consensus protocols and their practical implications
  • Skilled in benchmarking and identifying performance bottlenecks
  • Experience with live incident response and effective triage under pressure
  • Strong end-to-end systems thinking and ability to architect complex systems

Responsibilities

  • Build and maintain Docker/Kubernetes harnesses for infrastructure and scale testing
  • Consolidate CI/CD into standardized workflows and manage the full release lifecycle
  • Create a unified observability system for metrics, traces, and logs
  • Implement automated chaos and performance testing in CI for all releases
  • Manage the entire bug and vulnerability workflow, including incident response

Benefits

  • Opportunity to be a foundational hire in a small team
  • Focus on building a world-class platform for decentralized finance
  • Broad mandate with substantial impact on engineering practices
  • Exposure to cutting-edge technologies in blockchain and web3
  • Collaborative environment aimed at continuous improvement and learning
Full Job Description
Platform Engineering at Sei

We're building Sei into a world-class L1 for decentralized finance. This role exists to make the safe path the default path for every engineer on the team - observable, tested, reversible, and fast. You'll be a foundational hire on a small Platform Engineering team with a broad mandate.

What you'll own
  • Infrastructure & scale testing. Build and maintain Docker/Kubernetes harnesses for repeatable stress and scale testing, used by every core team as a pre-release gate. Run our multi-cloud footprint with explicit reliability and cost targets.
  • Release engineering & CI/CD. Consolidate CI/CD into reusable, standardized workflows. Own version tagging, hotfix paths, PR review scaffolding, and the full release lifecycle.
  • Observability. Single pane of glass for metrics, traces, and logs - correlated by block height, powered by OpenTelemetry. HA Prometheus, ELK, defined SLOs on every critical service.
  • Performance & chaos testing in CI. Automated chaos and performance tests gating 100% of releases. Regressions caught before merge, not by users.
  • Security & incident response. Run the bug and vulnerability workflow end to end - auditors, Immunefi, triage, postmortems. Every incident produces a new test, metric, or runbook.


What we're looking for
  • 5+ years building production systems at scale. You've designed and shipped infrastructure that other engineers rely on, and you understand it end to end - not just the surface API.
  • Security fundamentals. Threat modeling, common vulnerability classes, and how security work integrates into a development pipeline. You don't treat audits as a checkbox.
  • Distributed consensus understanding. You can reason about consensus protocols at the algorithmic level - safety vs. liveness, fault assumptions, the failure modes that show up in practice. You've debugged something non-trivial at this layer or studied it deeply enough to.
  • Benchmarking & performance bottleneck analysis. You design benchmarks that isolate variables. You profile under realistic load. You can walk into an unfamiliar system, find the bottleneck, and explain why it's the bottleneck before proposing a fix.
  • Live incident response. You've operated systems where outages had real consequences. You triage under pressure, communicate clearly, and turn postmortems into structural fixes that don't quietly expire.
  • End-to-end systems thinking. You've built systems, not just glued tools together. You have opinions on monitoring stacks, what belongs in CI vs. CD vs. runtime, and when to reach for chaos testing - and you can defend them.


Bonus
  • Blockchain or web3 infrastructure experience, especially with consensus, mempool, or storage layers.
  • Multi-cloud cost programs that didn't compromise reliability.
  • Experience integrating AI-assisted security tooling into a development pipeline.

About Whatnot

Whatnot is a Los Angeles-based startup that creates a place where avid collectors could come together over shared interests. Whatnot is a marketplace to buy and sell authentic collectible items. Whatnot was founded in 2019, in California.

Whatnot Careers

Joining Whatnot presents an unparalleled opportunity to become part of a leading team in the marketplace, where innovation meets diversity and professional growth. Whatnot is renowned for its unique culture that fosters leadership and promotes career advancement through continuous learning and development.

Explore Job Opportunities

Whatnot is actively seeking talented individuals who are eager to drive innovation and lead in a dynamic environment. The company offers a variety of job opportunities that cater to professionals looking to make a significant impact in their fields. With positions ranging from technology to marketing, Whatnot ensures that every team member’s skills are harnessed effectively.

Experience Professional Growth

At Whatnot, growth is not just a possibility—it is an expectation. The company is committed to the professional development of its employees through robust training programs, including leadership development and diversity training. These initiatives are designed to enhance skills and prepare individuals for future challenges and opportunities.

Engage in Meaningful Work

Every position at Whatnot is designed to challenge team members while contributing to the company’s overarching goals of innovation and service excellence. Employees are encouraged to take ownership of their projects and drive results that influence the company’s trajectory and success.

Internship Programs

For those starting their career journey, Whatnot offers internship programs that provide a comprehensive learning experience. Interns at Whatnot gain hands-on experience, working alongside seasoned professionals and participating in projects that offer real-world applications of their studies.

Benefits and Culture

Whatnot is dedicated to supporting its team members not only in their professional lives but also in their personal growth and well-being. The company offers competitive benefits packages that address health, financial security, and work-life balance. Whatnot’s culture is built on a foundation of respect and inclusion, where diversity is celebrated and every voice is heard.

Join the Team

Whatnot is hiring! Explore open positions that match your skills and interests. The company values curious, creative, and solution-driven team players. Prepare your resume and ready yourself for an interview where you can showcase your abilities and fit for the team.

Networking and Career Advancement

Whatnot believes in the power of networking to unlock new opportunities and insights. Employees are encouraged to engage with industry leaders and peers through various professional networking events sponsored by the company. These connections can lead to innovative ideas and collaborations that propel both personal and company growth.

Stay Connected

Keep up to date with the latest from Whatnot by following the company’s career blog. Gain insider perspectives, career tips, and industry-leading insights that you can apply to your professional life. Personalize your subscription to receive job alerts and the latest news tailored to your preferences.

Discover Whatnot

Whatnot invites you to explore the exciting and rewarding opportunities that await. Join a team where your career aspirations can be realized through dedication, hard work, and a commitment to excellence.
Learn more about Whatnot
Size
251 employees
Industry

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