About StackOne StackOne is the universal integration layer for modern SaaS products. We’ve raised $24m in 2 years, and we’re backed by top tier investors like Google Ventures and Workday Ventures. Our unified API platform lets vendors ship hundreds of native, white label integrations in days, not months, by abstracting away dozens of disparate third party APIs into a single, normalized interface. On top of those APIs, we provide AI Agent Actions so customers can build agentic workflows without wrangling OpenAPI specs. StackOne sits behind the scenes as an embedded iPaaS: SOC 2 compliant, multi-tenant, and invisible to end users powering integrations for future-of-work SaaS categories such as HR, Compliance, and AI Agents. Our customers are established B2B SaaS companies that: Sell to mid market and enterprise buyers Are building AI Agents in the near future Need deep, native integrations to win competitive deals and power their product Value time to integration over building connectors in house We typically close OEM and embedded licensing deals, multi-year (1 to 3 year) contracts, five to seven figure TCV, with a strong land and expand model. Key buyer personas are the CPO and CTO. Role overview As a Pre-Sales Engineer you will be the technical face of StackOne during the sales process. You will uncover real customer needs, craft solution architectures, deliver compelling demos, guide prospects through proof-of-concepts, and remove every technical barrier to closing the deal, while feeding product insights back to product & engineering. You will also ensure a smooth transition into onboarding with the Customer Success and Solutions Engineering (post-sales) team. You’ll report to our VP Sales and partner 1-to-1 with Account Executives. Expect 20-25 % travel for key customer visits and events. Your responsibilities Discovery & Qualification: Lead technical discovery alongside Account Executives to map business goals, existing stack and success criteria; quickly triage whether StackOne offers the right fit. Solution Design & Demo: Architect tailored integrations / workflows, build repeatable but story-driven demos, and present to audiences ranging from developers to C-suite. Proof-of-Concepts: Own PoC scoping, success metrics, hands-on setup and troubleshooting to prove value within agreed timelines. RFP / Security Questionnaires: Craft clear, convincing technical responses that highlight StackOne’s differentiators and compliance posture. Stakeholder Enablement: Coach Account Executives on product nuances; create reusable demo assets and best-practice templates for the wider PSE team. Feedback loop: Channel field insights to Product & Engineering, influencing roadmap and prioritising high-impact features. Thought leadership & Events: Support webinars, trade-shows and community events; occasionally act as SME on emerging areas like Gen-AI connectors. Core qualifications 3-6 yrs in pre-sales, solutions engineering or equivalent hands-on practitioner role within an API, infrastructure B2B SaaS, or embedded platform. Fluency in REST/GraphQL APIs, webhooks, OAuth2/SAML, and at least one modern language (Node, Python, Go, Java). Able to whiteboard complex architectures and tell a business-value story that resonates with both engineers and execs. Comfortable managing multiple concurrent PoCs and deadlines in a fast-moving startup environment. Strong written skills for RFPs and security questionnaires; clear, confident live demo delivery. Bonus points Familiarity with low-code integration platforms, iPaaS or workflow orchestration tools. Interest in Generative AI frameworks (LangChain, LlamaIndex) and how enterprises adopt them. Why Join Us? Join one of Europe’s fastest-growing startups Work with a veteran team of ex-employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and more Participation in the company’s employee share options plan 25 days holiday 1 additional day holiday per year of tenure Flexible work setup - we're hybrid-friendly £1,000 for your home office set up £500/year top-up Cycle2Work and Electric Cars scheme Private health insurance (including dental & optical) Health, fitness and gift card discounts Annual team offsite to sunny spots (last ones were in Spain and Portugal ☀️) Ready to help us change the game for SaaS integrations? Get in touch and let's chat! We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal-opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all employees.