Ostium is on a simple mission: make it possible for anyone with a digital wallet to trade stocks, commodities, currencies, and crypto with full transparency. No brokers, no freezes, no hidden spreads. We’re replacing the opaque, offshore brokerage model with a transparent, permissionless trading stack built onchain. Every trade, deposit, and withdrawal is verifiable through open, auditable code. We’ve raised $27.9M+ from General Catalyst, Jump, LocalGlobe, Susquehanna (SIG), GSR, Alliance DAO, Soma Capital, Balaji Srinivasan, Meltem Demirors, and others.
We're hiring a QA engineer (2–4 years experience) who understands DeFi. You'll own quality across our web and mobile frontends, not just running test cases, but thinking like a user who has real money on the line. You need to understand how perpetual trading works, what leverage means, how wallets connect, how transactions flow and where all of that can break.
Own quality across web and mobile frontends
Think like a real user with money on the line — hunt for edge cases, broken flows, and UX friction
Write and maintain automated test suites for the web app (Cypress, Playwright, or similar)
Test DeFi-specific flows — wallet connections, approvals, order types, transaction states, network switching
File detailed, actionable bug reports with reproduction steps engineers can immediately act on
Use browser dev tools and logs to investigate issues beyond surface-level symptoms
Work with engineering to verify fixes, catch regressions, and validate releases before they ship
Help build and improve CI-integrated test pipelines over time
Solid experience testing web and mobile applications.
Familiar with DeFi primitives like wallets, approvals, order types, on-chain vs off-chain flows, network switching, transaction states.
You should be able to look at a trading interface and intuitively know what edge cases to hunt for.
Experience with automation testing on web apps (Cypress, Playwright, or similar), writing and maintaining test suites, not just manual passes.
Comfortable reading logs, using browser dev tools, and filing bugs that engineers can actually act on.
Experience testing across multiple chains or L2s.
Familiarity with mobile testing frameworks (Detox, Appium).
Basic scripting ability (JS/TS or Python).
Experience with CI-integrated test pipelines.
Competitive compensation package
Opportunity to work with cutting-edge blockchain technology
Collaborative environment with highly skilled team members
Flexible work arrangements
Professional development opportunities
You're the person who finds the bug everyone else missed because you actually used the product like a real user would. You take ownership of quality and not just flagging issues but following them through to resolution. You're curious about how things work under the hood, even if you're not writing the code. High agency while obsessed with getting the details right.
If this sounds like you, reach out.