Principal Fullstack Engineer (AI)

TL;DR

Principal Fullstack Engineer (AI): Define and own the architectural direction for Console platform pillars, driving integration contracts, standards adoption, and consistency across teams. Focus on solving complex cross-cutting enterprise access control, navigation and entitlements architecture, and reducing coordination overhead through self-service integration patterns and contract-tested service interfaces.

Location: London

Company

DeepL is a global AI product and research company building secure, intelligent solutions for complex business communication needs.

What you will do

• Define and own the architectural direction for one or more Console platform pillars, including integration contracts and standards adoption.
• Lead cross-sub-team architectural decision-making by authoring RFCs and design documents adopted across engineering.
• Reduce coordination overhead by designing self-service integration patterns, documented contracts, and governed processes.
• Own the technical evolution of Console’s most complex cross-cutting systems (permission/access control, navigation, entitlements, and migration to contract-tested interfaces).
• Partner with engineering managers and product leads to align platform capability roadmaps and enable product delivery.
• Set and maintain engineering quality bar for Console using DORA metric targets, contract testing standards, feature flag practices, and progressive migration patterns; mentor engineers and run design reviews.

Requirements

• Demonstrated ownership of cross-team platform or shared-infrastructure systems where other engineering teams depended on and adopted architectural decisions.
• Strong full-stack web engineering depth across frontend and backend, with the ability to reason about integration contracts and system-level trade-offs.
• Track record of achieving technical alignment across teams without line management authority using written proposals, facilitation, and clear trade-off communication.
• Experience building or governing access control, permissions, or identity systems in an enterprise SaaS context, including commercial and security implications.
• Comfort operating in ambiguous ownership spaces by establishing clarity through documentation and shared standards.
• Evidence of force multiplication through mentorship, standards-setting, and architectural work that reduces others’ complexity.

Culture & Benefits

• Hybrid work schedule with office attendance twice a week.
• Flexible working hours aligned with team time zones.
• 30 days of annual leave (excluding public holidays) and access to mental health resources.
• Virtual Shares for an ownership mindset and alignment with company growth.
• Regular in-person team events and monthly full-day hacking sessions (Hack Fridays).
• Competitive benefits package tailored to location.

Hiring process

• Application review followed by interviews to assess architectural leadership, cross-team alignment, and full-stack depth.
• Discussion of relevant experience with enterprise access control/identity systems and contract-tested integration patterns.
• Final evaluation focused on mentorship/force-multiplication and ability to operate in ambiguous ownership spaces.