Founding Engineer (Backend)
Triage
Triage is an applied research lab building adaptive security and safety alignment infrastructure for AI systems: defending against novel attack vectors and catching misalignment at inference-time in deployed systems. In December 2025, Triage raised a $1.5M pre‑seed round led by BoxGroup. We operate as an inference proxy — base URL swap, transparent to the customer's SDK. Every request in our customers' production flows through us. Our latency budget is measured in single‑digit milliseconds on the fast path. Our team is small, technical, and in‑person. We like people who are truth‑seeking, opinionated about systems, and ship. About the Role We're hiring a Founding Engineer (Backend) to own the systems that every customer request flows through. The work spans the proxy path itself, the per‑tenant isolation layer that makes our detection cascade possible, and the deployment surfaces (VPC, on‑prem, eventually air‑gapped) that unlock regulated enterprise buyers. This is not a "backend for a SaaS" role. Correctness and latency are both load‑bearing. When a customer points their SDK at us, we are in the hot path for every model call their agents make. What you'll do Own the dual‑pass detection pipeline: sub‑millisecond fast‑path filtering with async deep‑pass validation, including the tail‑latency and correctness guarantees under load Build and maintain the inference proxy: streaming, multi‑provider routing across frontier and open‑weight models, retry semantics, auth, per‑tenant isolation Ship per‑tenant LoRA serving infrastructure and the DPO feedback loop that turns triaged production alerts into per‑customer adapter improvements Deliver enterprise deployment surfaces — VPC from day one, on‑prem for regulated customers, air‑gapped where required Own the data pipeline connecting production telemetry back to adapter training and evaluation infrastructure You may be a fit if You build production‑grade distributed systems where latency and correctness both matter. Inference infrastructure, API gateways, proxy systems, CDN edge, or security‑adjacent platforms all map well. Deep systems fluency — you reason naturally about tail latency, backpressure, head‑of‑line blocking, and why adding a retry usually makes things worse Strong in Python, and in at least one of Go, Rust, or C++ for performance paths You've shipped VPC or on‑prem deployments, or you're genuinely excited to learn. This will be a significant part of the job. You understand why security infrastructure is architecturally different from SaaS, and why cloud‑only is disqualifying for our customers Currently pursuing a Bachelor's, Master's, or PhD, or prior industry experience. Either works — we care about what you've built. #J-18808-Ljbffr Triage
- At Falconer, we’re transforming how engineers create, access, and share knowledge. We’re looking for a Founding Backend Engineer to help us build an AI-powered knowledge platform that companies love. As a founding engineer, you won’t just help shape our product development...SuggestedWork experience placementWork at officeFlexible hours
$130k - $180k
...enterprises. Qualifications 5+ years experience in full-stack engineering, with senior-level expertise Experience building 0 → 1 in a startup... ...Experience in scaling and working with enterprise clients Founding engineer experience at pre-seed through series A or B startup...Suggested- ...Design, develop, and maintain scalable backend services to help us serve millions of users... ...features. Collaborate with frontend engineers to design and implement RESTful APIs and... ...Previous experience as a founder or founding engineer is highly preferred. Hard skills...SuggestedContract workWork experience placementWork at officeImmediate start
- Blockchaincapital.com is seeking a Founding Senior Backend Engineer in San Francisco to lead the development of the backend infrastructure for the Button protocol. The ideal candidate should have significant experience in backend development with modern programming languages...Suggested
$200k - $250k
...Founding Backend Engineer, On-site - San Francisco, CA Schedule: In office, five days per week A well funded seed stage AI company is building advanced agentic systems that automate complex workflows inside real enterprise software. The team is developing the platform...SuggestedWork at officeImmediate start$160k - $200k
...Founding Backend Engineer Client is a fast-growing social shopping platform co-founded by Phoebe Gates and Sophia Kianni. The platform currently serves over 350,000 users and boasts a 90% retention rate. Phia combines community, personalization, and AI-driven recommendations...Full timeH1bRelocationVisa sponsorshipRelocation packageNight shift- We are looking for a founding backend engineer with unusually strong engineering and design taste. The world’s most critical infrastructure—banking, airlines, utilities—is held together by millions of lines of COBOL and mainframe logic written decades ago. The engineers...H1bVisa sponsorshipWork visaRelocation package
- We are hiring a Founding Software Engineer in San Francisco. We are building a small, talent-dense team. This role will define the engineering... ...and developer experience. Architect, build, and scale core backend systems powering document intelligence and VLM-based...
$175k - $300k
...300K cash. You will own a meaningful piece of the company. High talent density: Be a part of a great founding team in SF. Shivaal Roy (CTO) was a founding engineer at Glean ($100M+ ARR today) and managed the Assistant and Search teams, where he solved similar problems...$140k - $180k
Our client, an early-stage AI Startup, is hiring a Founding Engineer to join their team in San Francisco. The successful candidate will play a key role in designing and scaling a multi‑tenant, AI‑native platform, from building the semantic foundation that allows autonomous...$160k - $225k
The Role As a Founding Engineer at Straia, you’ll work directly with a small team including directly with our CEO (Ryan), CTO (Alan) and CPO... ...shipping full-stack applications, with a strong emphasis on backend systems (Node.js, TypeScript, Postgres) Deeply technical , with...Work at office$175k - $225k
...customers. She will pick the best candidates from Jack's network The next step is to speak to Jack. Job Title: Founding Engineer - Backend & Data Platform Salary: $175,000 - $225,000 + Equity Company Description: Greenline - Fast-growing fintech startup...Self employmentRemote work- ...The Role We are looking for a Founding Backend Engineer to lead the design and development of the backend infrastructure that powers the Button protocol a next generation agentic finance app built to give retail traders the access, tools, and capital efficiency that...
$250k - $400k
A tech startup in San Francisco is seeking a founding engineer with strong backend and infrastructure skills. This role involves leading a team, designing intuitive APIs, and building high-performing systems that leverage AI capabilities in email communication. Candidates...- Triage is seeking a Founding Engineer (Backend) in San Francisco. This role involves owning the systems that manage customer requests with a focus on correctness and low latency. The candidate will build and maintain the inference proxy and deploy solutions for regulated...
- Soulside AI in San Francisco is searching for a Backend Engineer to join their founding team. This role offers the unique chance to shape the technical foundation of a revolutionary mental health care platform. The ideal candidate will have expertise in Spring Boot, AWS...Remote job
- Kastle is seeking a talented engineer to architect and own core systems for AI voice operations in San Francisco. In this role, you will have substantial ownership over your work and will tackle challenges to build high-performance, real-time systems primarily in Python...
$100k - $200k
...About the job Founding Backend Engineer (Sales tech) Location: Hybrid in San Francisco, New York City or Vancouver Work type: 3 days in office, 2 days remote Our client's team is building an AI-first revenue platform a collective intelligence layer that...Work at officeRemote work- A tech startup in San Francisco is seeking a Founding Engineer with a focus on backend and infrastructure. Responsibilities include designing APIs for AI agents, architecting scalable systems, and maintaining documentation. The ideal candidate has prior experience in a...
$150k - $250k
AgentMail (YC S25) is seeking a Founding Engineer in San Francisco to design intuitive APIs and architect high-performance systems. This role requires prior engineering experience and a proven ability to ship software used by real users. The compensation package includes...- Hypercubic is looking for a founding backend engineer based in San Francisco, California. In this role, you'll prototype and productionize AI-powered systems, directly working with the CTO. This position offers meaningful ownership over product direction and engineering...
- A pioneering technology company is seeking a Founding Back-end Engineer to build and scale their back-end systems. This remote role requires expertise in NodeJS and Postgres, with a focus on developing efficient APIs and managing cloud resources. Ideal candidates will...Remote work
$200k - $325k
Aionia Group in San Francisco seeks a founding team member to architect and ship production-grade AI... ...into scalable implementations and maintaining backend services and APIs. Candidates should have strong backend engineering skills, a relevant degree, and be comfortable...$130k - $200k
...San Francisco, is looking for a talented engineer to architect and own core systems that... ...leverage expertise in high-performance backend systems, especially in Python, to deliver... ...-paced environment alongside a world-class founding team. #J-18808-Ljbffr Kastle (YC S24)- ...8 years Stage: Seed - Series B Role Type: Early hire / founding engineer Why This Role Exists You'll help build the core product... ...Build end-to-end product features across frontend and backend Ship quickly in 0-1 environments Design APIs, schemas,...
$160k - $220k
...About the job Founding Full-Stack Engineer Founding Full-Stack Product Engineer (AI-Native) On-Site | San Francisco | Full-Time $... ...What Youll Own End-to-end product engineering: backend, frontend, infrastructure AI-driven product features (context...Full timeH1b$180k - $230k
...in the AI-powered sales automation space is hiring its first Founding Engineer. You'll join the CTO as a core member of a tiny, high-caliber... ...use, prompt engineering, and conversation flow. Production backend development experience in Python (services, APIs, backend infrastructure...Remote work- ...century. Dryft is powering the next. THE ROLE As Founding Fullstack Engineer , you'll be the brain behind Dryft's decision intelligence... ...Have shipped production code end-to-end, are strong in backend & infra and comfortable shipping basic frontend features....Relocation
$150k - $250k
...across the United States to help them hire. Title of Role: Founding Fullstack Engineer Location: San Francisco, CA (On-site, 6 days/week)... ...the ground up. What You Will Do Build scalable backend systems for decision intelligence products Develop systems...Work at officeRemote workRelocationVisa sponsorshipRelocation package- ...Jack & Jill, a fast-growing HealthTech startup, is seeking a Founding Full Stack Engineer to own the entire technical stack for a platform used by the largest health systems. You'll design systems that impact nurse retention and patient outcomes. You'll enjoy a rare opportunity...
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