Full Stack Engineer

At Kertoa, we’re on a mission to get better outcomes from programmatic advertising campaigns without adding more complexity.Our algorithms help boost campaign performance through curated PMP deals. These deals are activated directly within Demand Side Platforms (DSPs) and continuously optimised to help clients beat their campaign benchmarks.We work with enterprise and mid-market advertisers globally, deploying our technology around their requirements. Our product is already in active use, so you’ll be shipping to a live environment, not a throwaway prototype.We’re looking for a Full-Stack Engineer who wants to help us push the boundaries of supply-side optimisation and play an important role in developing the technology behind Kertoa.We believe in high standards, hard work, and delivering results. If that resonates, you’ll feel at home here.The roleWe are hiring a full-stack engineer to join a small team and own features end to end: interface, API, data, and third-party integrations. Day to day that is React, Python, and MongoDB.You will work across the product, not in a frontend-only or backend-only lane. Business rules must stay consistent from the UI through to external systems. When something looks right on screen but wrong downstream, you will debug it.What you will doDesign, build, and ship product features across UI and APIIntegrate with external vendors and keep those integrations reliableAdd tests with your changes and help verify work in a shared environmentImprove quality: access control, validation, error handling, operational toolingCollaborate with product and QA; hand off work with evidence, not “should work”Learn the domain on the job, advertising experience is useful, not requiredWhat we look forRequiredProven full-stack delivery: you have shipped UI and API togetherReact, Python, and MongoDB (or very close equivalents and a willingness to work in this stack)Experience calling third-party APIs (auth, retries, awkward vendor behaviour)Tests as a normal part of shippingClear written communicationAbility to work in an existing codebase and match established patternsStrong plusB2B / ops / workflow productsMulti-tenant access controlBrowser-level testing against a shared environmentSmall-team or early-stage experienceAdvertising or media technology (nice, not required)How we workSmallest correct change; no drive-by rewritesFeatures include testsWork that touches an external vendor is done when it is deployed and confirmed in that vendor’s system, not only in our appWe do not use live customer records for developmentWhat this role is notNot a design-system or pixel-only frontend roleNot a backend-only role with no UINot a greenfield rewrite, you will extend a working productNot a large on-call organisation; it is a small team with real vendor side effectsRole DetailsType: Full-time Location: Hybrid (4 Days)Reports to: Engineering / Founding team