| Location | San Francisco, CA |
Senior Software Engineer at JustAI | Y Combinator
Open menuAboutWhat Happens at YC?ApplyYC Interview GuideFAQPeopleYC BlogCompaniesStartup DirectoryFounder DirectoryLaunch YCLibraryPartnersResourcesStartup SchoolNewsletterRequests for StartupsFor InvestorsVerify FoundersHacker NewsBookfaceSafeFind a Co-FounderStartup JobsLog inApplyJustAIAgentic Marketing PlatformSenior Software Engineer$120K - $200K•0.10% - 0.50%•San Francisco, CA, US / Remote (US)Job typeFull-timeRoleEngineering, BackendExperience3+ yearsVisaUS citizen/visa onlyConnect directly with founders of the best YC-funded startups.Apply to role ›Neha MittalFounderNeha MittalFounderAbout the roleRole Overview As a Senior Software Engineer, you'll help us architect and scale our platform from the ground up. In this role, you'll play a pivotal role in designing and integrating ETLs, and driving effective monitoring and observability as you architect and operate core infrastructure and data systems at scale.
What You'll Do
Design the system architecture for an AI-first marketing platform Drive new ETL pipelines to handle customer event data at scale Define industry standards for leveraging agentic AI to personalize marketing Power the marketing decisions for large companies, processing billions of data points every day
Qualifications
3+ years of industry experience in backend/infra engineering You have experience designing data pipelines and processing event streams at scale Proficiency in SQL and understanding of database design Experience in building platforms and 0-1 systems You are a quick learner, and you thrive in a fast-paced, constantly evolving environment
Why Join JustAI
High ownership, high impact - your work defines how AI meets real customer workflows Founding-stage startup backed by YC & Peak XV (Sequoia), and growing fast Work with leadership from Twitter, Pinterest, and Goldman Sachs Competitive salary and meaningful equity
About JustAIThe future of Marketing is 1-1 hyper-personalized messaging. However, marketers spent multiple cycles setting up an "octopus" on CRM journey builders to manually write content for each persona and segment. Further, A/B testing is sequential and takes weeks to show results. We drift away from the old school A/B testing world to dynamic testing. Companies can test 100+ messaging variants within a month, let AI optimize traffic for winning variants, and walk away with insights without operational setup overhead for every A/B test. We put companies in a state of continuous "always-on" testing. JustAIFounded:2024Batch:W24Team Size:5Status:ActiveLocation:San Francisco FoundersNeha Mittal FounderNeha Mittal FounderFooterY CombinatorMake something people want.ProgramsYC ProgramStartup SchoolWork at a StartupCo-Founder MatchingResourcesStartup DirectoryStartup LibraryInvestorsDemo DaySafeHacker NewsLaunch YCYC DealsCompanyYC BlogContactPressPeopleCareersPrivacy PolicyNotice at CollectionSecurityTerms of UseTwitterTwitterFacebookFacebookInstagramInstagramLinkedInLinkedInYoutubeYouTube© 2026 Y Combinator