Senior Full-Stack Engineer - Onboarding (SDK)

Taktile helps financial institutions make smarter, safer decisions with the power of AI. Our software gives teams the tools to automate complex decisions, from customer onboarding and underwriting to fraud detection, with full visibility and control. By combining AI with a rich ecosystem of financial data, we enable companies to adapt their decision‑making in real time as markets, customer behaviour, and risks evolve.

What You'll Do

• Architect the SDK from scratch: design and build a client‑side JavaScript/TypeScript SDK that orchestrates multiple third‑party vendor scripts behind a unified, headless API.
• Build the hosted verification experience: create a secure, embeddable web application that renders interactive identity verification flows with a polished, brand‑able UX.
• Own reliability end‑to‑end: establish versioning strategies, staged rollouts, and CI/CD pipelines for client‑side code that runs in customer browsers.
• Solve hard integration problems: wrangle vendor SDKs that each have their own quirks, lifecycle hooks, and failure modes, and make them work together seamlessly.
• Shape the product and the team: collaborate with Product, Design, and customers to define the SDK's developer experience. As the team grows, you’ll have the opportunity to step into a tech lead role.
• Work directly with customers: engage with early adopters to understand their integration environments and ensure the SDK works flawlessly in the real world.

Requirements

• Hybrid role based in Berlin or London. We collaborate in person regularly and don’t offer remote‑only for this position.
• Fluent English required. You’ll write design docs, review PRs with context, and occasionally join customer calls.
• Strong engineering fundamentals across the full stack: you’re equally comfortable designing clean APIs and building responsive, accessible front‑end experiences.
• Deep understanding of how browsers work: the DOM, security models (CSP, CORS, iframe sandboxing), caching, script loading, and performance.
• Comfortable operating systems in production and participating in incident response as part of a team rotation.

Required Experience

• 5+ years of professional software engineering experience.
• At least 2 years building and shipping a client‑side SDK, embeddable widget, or developer‑facing JavaScript library used by external consumers.
• Production experience with TypeScript/JavaScript on both client and server.
• You’ve built modern front‑end applications and understand bundling, tree‑shaking, and cross‑browser compatibility deeply.
• Experience with iframe‑based architectures, postMessage communication, and sandboxed execution environments.
• Proficient in backend development (Python is a plus); you can build the APIs and configuration services that power the SDK.
• Prior industry experience with public cloud providers (preferably AWS).

Ideal, But Not Required

• Experience in identity verification, fraud prevention, or fintech – you’ve worked with providers like Socure, Vouched, Onfido, Fingerprint, or ThreatMetrix.
• Familiarity with media APIs (camera access, image capture, WebRTC) and the nuances of building permission‑driven UX flows.
• Experience building developer tools, documentation, or SDKs with a focus on great developer experience.
• Previous experience as a tech lead or strong desire to grow into one; you enjoy mentoring, setting technical direction, and making architecture decisions that scale.
• Knowledge of security and compliance considerations (SOC2, PII handling) for client‑side applications in regulated industries.

Our Offer

• Work with colleagues that lift you up, challenge you, celebrate you and help you grow.
• Experience a truly flat hierarchy and communicate directly with founding team members.
• Learn from experienced mentors and achieve tremendous personal and professional growth.
• Receive a top‑of‑market equity and cash compensation package.
• Get access to a self‑development budget you can use to e.g. attend conferences, buy books or take classes.
• Receive a new Apple MacBook Pro, as well as meaningful home office set‑up.

Our Stance

We’re eager to meet talented and driven candidates regardless of whether they tick all the boxes. We’re looking for someone who will add to our culture, not just fit within it. We strongly encourage individuals from groups traditionally underestimated and underrepresented in tech to apply. We seek to actively recognize and combat racism, sexism, ableism and ageism. We embrace and support all gender identities and expressions, and celebrate love in its many forms.

About Us

Taktile helps financial institutions make smarter, safer decisions with the power of AI. Our mission is to build the world’s leading platform for automated decision‑making in financial services, setting the standard for how AI is applied responsibly and effectively in this industry.