Full stack software engineer at Delty | Y Combinator

AboutWhat Happens at YC?ApplyYC Interview GuideFAQPeopleYC BlogCompaniesStartup DirectoryFounder DirectoryLaunch YCStartup JobsAll Jobs◦ Engineering◦ Operations◦ Marketing◦ SalesInternshipsStartup Job GuideYC Startup Jobs BlogFind a Co-FounderLibrarySAFEResourcesStartup SchoolNewsletterRequests for StartupsFor InvestorsVerify FoundersHacker NewsBookfaceOpen main menuApply for W2026 batch.ApplyDeltyAI staff engineer: software architect that leads coding agentsFull stack software engineer$80K - $150K•San Francisco, CA, US / RemoteJob typeContractRoleEngineering, Full stackExperience3+ yearsVisaUS citizenship/visa not requiredSkillsReact, Amazon Web Services (AWS), Prompt Engineering, TypeScript, Machine LearningConnect directly with founders of the best YC-funded startups.Apply to role ›Lalit KunduFounderLalit KunduFounderAbout the roleAbout Us
Delty is building the world’s first “AI Staff Engineer.” Unlike typical code-generation tools, Delty is trained on a team’s codebase, documentation, and system history — giving it a system-level understanding of architecture, conventions, and constraints. Delty helps engineering teams design enterprise-scale software systems, make architectural decisions, and enable AI coding agents to work with real system context.
Delty was founded by former engineering leaders from Google, including co-founders with deep experience at YouTube and in large-scale infrastructure. You’ll get to work alongside people who built massive systems at scale — a chance to learn a lot and contribute meaningfully from day one.
We believe in solving hard problems together as a team, iterating quickly, and building software with long-term thinking and ownership.

What You’ll Do

Work full-stack: design and build features spanning front-end, back-end, data storage and processing.
Build new product modules and services from scratch — or evolve existing ones — guided by context-aware system design.
Work with AI and machine learning: integrate large-language models (LLMs), process large or long-form text data, apply traditional ML (e.g. regression, data pipelines), and build tooling around AI-driven flows.
Make architectural decisions — choose frameworks, data models, APIs, storage solutions — balancing trade-offs between performance, scalability, maintainability, and complexity.
Collaborate closely with co-founders and other engineers to translate product vision into a working, maintainable codebase.

What We’re Looking For

At least 3 years of full-stack engineering experience, including substantial work with AI/ML.
Strong skills across front-end, back-end, databases/data storage — and demonstrated ability to design end-to-end systems.
Experience working with or integrating AI/ML — LLMs, data pipelines, long-form text processing, traditional ML like regression or statistical modeling.
Good design sense and architectural thinking: you understand trade-offs (scalability vs complexity, speed vs maintainability) and can choose wisely based on constraints.
Comfort working in a fast-paced startup-style environment: nimble, iterative, high ownership.
Bonus: prior startup experience, or even having been a founder — we value entrepreneurial thinking, self-direction, and willingness to wear multiple hats.

Why join

Learn from seasoned Google engineers: As former Google engineers who built systems at YouTube and Google Pay, we’ve operated at massive scale. Working alongside us gives you a chance to build similar systems and learn best practices, scale thinking, and software design deeply.
High impact: At a small but ambitious team, your contributions will influence architecture, product direction, and core features. You will have real ownership and see the effects of your work quickly.
Grow fast: We’re iterating rapidly; you’ll be exposed to the full stack, AI/ML pipelines, system architecture, data modeling, and product-level decisions — a fast-track to becoming a senior engineer or technical lead.
Challenging and meaningful work: We’re tackling the hardest part of software engineering: bridging AI-generated prototypes and robust, scalable enterprise-grade systems. If you enjoy thinking deeply about systems and building reliable, maintainable foundations — this is for you.

About DeltyDelty, an AI staff enginer, designs software systems and makes coding agents better. Backed by world-class VCs, built by ex-Googlers.
DeltyFounded:2025Batch:X25Team Size:4Status:Active FoundersLalit Kundu FounderLalit Kundu FounderCatherine Zhao FounderCatherine Zhao FounderFooterY CombinatorProgramsYC ProgramStartup SchoolWork at a StartupCo-Founder MatchingCompanyYC BlogContactPressPeopleCareersPrivacy PolicyNotice at CollectionSecurityTerms of UseResourcesStartup DirectoryStartup LibraryInvestorsSAFEHacker NewsLaunch YCYC DealsMake something people want.ApplyTwitterTwitterFacebookFacebookInstagramInstagramLinkedInLinkedInYoutubeYouTube© 2025 Y Combinator

Delty, a company backed by Y Combinator and supported by a team of former Google engineers, is pioneering the role of the “AI Staff Engineer.” Founded in 2025, Delty’s core function revolves around designing and improving software systems, particularly through the integration of AI coding agents. The company’s origins trace back to individuals with extensive experience at YouTube and Google, bringing a perspective honed in building and scaling large-scale infrastructure systems. Delty’s approach distinguishes itself from traditional code-generation tools by leveraging a team’s existing codebase, documentation, and historical system data to establish a system-level comprehension of architecture, conventions, and constraints.

Specifically, Delty's work entails a comprehensive, full-stack engineering role, demanding proficiency across front-end, back-end, and data storage technologies. Candidates are expected to design, build, and maintain features, adapting existing modules or initiating entirely new services, always guided by a contextual understanding of the system’s design. A key component of the role necessitates interaction with large-language models (LLMs), particularly in processing large or lengthy text data, alongside the application of traditional machine learning techniques such as regression and data pipelining. It is anticipated that individuals will need to make critical architectural decisions concerning frameworks, data models, APIs, and storage solutions, carefully balancing factors like performance, scalability, maintainability, and the inherent complexity within the system.

The company’s technical demands, as articulated within the job description, prioritize at least three years of full-stack engineering experience, with demonstrable skills in AI/ML integration. A strong design sensibility and an understanding of trade-offs – considering factors like scalability versus complexity or speed versus maintainability – are highly valued. Furthermore, Delty seeks candidates comfortable operating within the dynamic environment of a startup, emphasizing nimbleness, iterative development, and high levels of ownership. The team's overarching goal is to bridge the gap between AI-generated prototypes and robust, scalable enterprise-grade systems—a demanding undertaking that promises rapid professional growth and significant impact. Individuals with prior startup experience or entrepreneurial thinking are viewed as particularly advantageous, reflecting a commitment to self-direction and a willingness to assume multifaceted responsibilities. By leveraging the expertise of former Google staff and a Y Combinator backing, Delty aims to fundamentally reshape the landscape of software development, incorporating AI’s capabilities seamlessly into the foundations of complex systems and encouraging innovation across a wide range of industries.