--- title: 'Founding Full-Stack Engineer at Zalos' canonical: 'https://feeny.ai/job/founding-full-stack-engineer-zalos-london-j0xrj88h5m71' type: 'job' last_seen: '2026-09-09' --- # Founding Full-Stack Engineer at Zalos - **Company:** Zalos - **Location:** London, United Kingdom - **Employment:** full-time - **Work type:** onsite - **Posted:** 2026-05-27 - **Last confirmed live:** 2026-09-09 - **Apply:** https://jobs.gem.com/zalos-ai/am9icG9zdDohk5f8jI1Rbye-6Lww3pXX ## Job description ## About the role As Zalos's Founding Full-Stack Engineer, your job is to build the product experience that makes this real. You'll be designing and shipping the application surfaces, backend services, and workflow infrastructure that turn messy enterprise work into correct, auditable action across systems of record. This is a hard, important part of the product. It's entirely yours to own. ## What we're building Enterprise software was built to store data and enforce process. It was never built to be used by humans who have better things to do. The result: highly trained people wasting hours every day fighting screens instead of doing the actual work. Zalos attacks this from three angles: - Intent-to-action: A user describes an outcome. Zalos figures out which systems to touch, in which order, with which data, and executes it with the right approvals and a clean audit trail. - Cross-system workflows: Event-driven chains that span SAP, Salesforce, and ServiceNow simultaneously. - Computer-use for the long tail: Not every enterprise workflow has a reliable API. We use computer-use agents to automate the 30 to 40 percent of processes that live in screens, VDI sessions, and legacy thick clients. ## What you'll work on - Design and own the core agent architecture: how we take a natural language intent, decompose it into steps, call the right APIs and UI agents, handle failures gracefully, and close the loop with the user - Build reliable, production-grade LLM pipelines covering context management, tool use, structured outputs, and multi-step reasoning across systems with real enterprise data - Work directly with the founders and customers to understand where AI fails in real enterprise workflows and translate that into better systems - Set the technical standards for how we build AI at Zalos Must haves - You've shipped AI-powered features that real users depend on in production. You know what breaks and how to prevent it - Deep hands-on experience with LLM APIs, agentic patterns, and tool/function calling - You think about reliability, latency, and cost as first-class engineering concerns, not afterthoughts - You build tests/evals before you ship, not after something breaks in front of a customer - High ownership: you take something from an ambiguous problem statement to a clean, working solution with minimal hand-holding - You're pragmatic. Startups are always on fire somewhere. You know when to let something burn and when to drop everything Nice to haves - Computer-use or browser automation work with tools like Playwright, browser agents, or UI parsing - Fine-tuning or RLHF on domain-specific tasks - Prior founding engineer or early-stage startup experience The team you'll work with You'll work directly with the founders from day one. No engineering manager in the way, no sprint planning theatre. ## Why Zalos - The market is real and enormous. The system integration market alone is $380B. - You'll work on genuinely hard AI problems. Reliable agents over messy enterprise systems, computer-use for legacy UIs, cross-system orchestration with audit trails. - Paying customers from day one. We're not pre-product. You'll see your work matter in real enterprise workflows within weeks of joining. - Small team, high trust. You'll have a direct line to founders and customers. Your opinions shape the product. ## About the interview We move fast and respect your time. No leetcode. No whiteboard puzzles. 1. 15-min intro call with a founder. We'll walk you through what we're building and what we need. You'll tell us what you've shipped. 2. Take-home technical task. No trick questions. We want to see how you think, not how you memorize. 3. 1-hour technical deep-dive with our CTO. Walk through your design, discuss tradeoffs, get into the weeds on production reliability. 4. 3-day paid work trial. Build something real with us. This is the most predictive step we have. 5. Offer. If we're aligned, you'll have an offer within a week of the trial. ## About Zalos ## Company Overview - **One-liner**: Zalos builds computer agents that automate repetitive finance operations, such as reconciliation and categorization, by logging into existing enterprise systems and executing tasks with a full audit trail. - **Entity Type**: Private (Seed-stage; Y Combinator F25 batch) - **Headquarters**: San Francisco, California, USA (also offices in London, UK and Wilmington, Delaware, USA) - **Founded**: 2025 - **Founders**: William Fairbairn, Hung Hoang ## Core Business - Primary industry: Finance operations automation, enterprise software, artificial intelligence - Target customers: Enterprise finance teams (Office of the CFO) – B2B, mid-market to Fortune 500 - Mission or purpose: To transform the 1,200 daily screen toggles and manual finance work into automated, agent-driven processes, freeing finance teams to focus on strategic decisions. ## Products & Services - **Zalos Computer Agents**: AI-powered agents that log into ERPs (e.g., SAP, NetSuite), banking portals, and card platforms; handle 2FA and CAPTCHA; automate reconciliation, categorization, form-filling, and data ingestion. The agent learns from human exceptions and improves over time. All actions are recorded for audit and compliance. [zalos.ai](https://www.zalos.ai/) ## Market Standing - **Valuation/Market Cap**: Not disclosed; total funding of $4.1M as of March 2026. - **Key Metric**: Total Funding – $4.1M (Seed round $3.6M in March 2026, with 26 investors; Pre-seed $500K in September 2025 led by Y Combinator). - **Notable Investors/Partners**: Y Combinator (lead investor in pre-seed), plus 26 other investors in the seed round. [linkedin.com/company/zalos](https://www.linkedin.com/company/zalos) - **Growth Signals**: SOC 2 Type II certified (March 2026); paying enterprise customers; small team of 10 moving fast; active job postings for Senior AI Engineer and Founding Product Engineer; headcount span across US, UK, and Vietnam. ## Competitive Advantages - **Computer agent approach**: Agents operate directly on existing finance systems (ERPs, banks, portals) without requiring API integrations or system replacements – a key differentiator for enterprises locked into legacy systems. - **Self-improving**: Each human exception teaches the agent, making the automation more robust over time (reinforcement learning feedback loop). - **Enterprise-grade security**: Full screen recording of every automation step for audit trail; SOC 2 Type II certified. - **Founder expertise**: William Fairbairn was UK General Manager at Agicap ($800M valuation) and a McKinsey alum; Hung Hoang built Apple Pay products and worked on AI at Apple and other startups. [ycombinator.com/companies/zalos](https://www.ycombinator.com/companies/zalos) ## Strategic Focus - Expand the agent’s coverage across more finance workflows (e.g., vendor onboarding, payment routing, debt covenant monitoring). - Scale the small team (currently 10) to build out product and engineering – especially computer agent intelligence and enterprise integrations. - Continue to win enterprise customers by proving compliance and ROI (e.g., saving 4 days per month per finance manager). ## Why Work Here - **Culture**: Early-stage, YC-backed startup with a “small team that moves fast.” Joining means defining the product and AI approach from the ground floor. - **Remote/Hybrid/Office**: Offices in San Francisco, London, and Wilmington – likely a hybrid or flexible model given distributed team (US, UK, Vietnam). - **Notable perks**: Strong seed funding, fully remote collaboration possible, direct impact on the company’s growth, and the chance to work on a “deeply unsexy” but massive problem: automating the world’s largest ERP systems. - **Open roles**: Senior AI Engineer and Founding Product Engineer (as of latest data). [jobs.gem.com/zalos-ai](https://jobs.gem.com/zalos-ai) ## Sources 1. [zalos.ai](https://www.zalos.ai/) 2. [linkedin.com/company/zalos](https://www.linkedin.com/company/zalos) 3. [ycombinator.com/companies/zalos](https://www.ycombinator.com/companies/zalos) 4. [jobs.gem.com/zalos-ai](https://jobs.gem.com/zalos-ai) ## Other roles at Zalos - [Founding Full-Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-weekday-san-francisco-gx7zd7s27wey) — San Francisco, CA - [Founding Full-Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-deepline-com-new-york-mv35r4szt57c) — New York, NY - [Founding Full-Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-truth-systems-san-francisco-egsyv2dhtxtm) — San Francisco, CA - [Founding Full-Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-dryft-san-francisco-t2xbt360hmpa) — San Francisco, CA - [Founding Full-Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-jobreel-california-y52cbnbr1hj9) — California - [Founding Full-Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-sunset-remote-25j5bcnhfkm0)