Principal Software Engineer - Fullstack, AI (all genders)

We are looking for an experienced Principal Software Engineer (Fullstack, AI) to join the Learner Experience Cluster at Babbel and help shape the technology behind impactful, customer-facing learning experiences used by millions of learners worldwide.

A Principal Software Engineer at Babbel drives outsized, durable impact across multiple teams by shaping technical direction, improving system-level outcomes, and scaling the effectiveness of others. This is a role defined by influence, planning, and strong role modeling — not authority or heroics.

As a Principal Software Engineer in the Learner Experience Cluster, you operate at the intersection of deep technical judgment, product thinking, and organizational impact. You care deeply about how technology enables learning outcomes — and you bring the architectural range to keep complex, customer-facing systems coherent as they grow.

You are also fluent in AI-native engineering workflows and motivated to evolve how your teams leverage AI across the software development lifecycle. You combine fullstack excellence with pragmatic, metrics-driven judgment about where AI creates real value — and you model that judgment for others.

Your impact is visible across teams, sustained over time, and focused on delivery speed, reliability, developer productivity, and learner experience.

What success looks like:

• Engineers across the cluster are measurably more effective — faster at design, implementation, and review — because of standards, patterns, and enablement you drove.
• AI is integrated into engineering workflows in ways that are practical, evaluated, and repeatable — not experimental noise.
• Key architectural decisions affecting multiple teams have clear rationale, documented trade-offs, and visible adoption.
• At least one senior engineer in the cluster grew in scope or capability as a direct result of your mentorship or technical leadership.

You will:

• Drive architectural coherence and technical direction across multiple customer-facing systems and teams.
• Design and evolve high-leverage APIs, data models, and distributed systems that power learner journeys, personalization, and experimentation.
• Establish shared patterns, abstractions, and standards that reduce fragmentation and increase engineering leverage.
• Act as a role model for AI-native workflows across design, coding, testing, code review, debugging, and incident response.
• Champion effective and responsible usage of AI-assisted development tools and scalable prompting practices.
• Identify and implement opportunities where AI can measurably improve developer productivity, delivery speed, and production quality.
• Define guardrails and evaluation approaches to ensure AI usage is secure, reliable, and aligned with engineering standards.
• Improve delivery performance by advancing continuous delivery, observability, and production excellence practices.
• Anticipate cross-team risks and dependencies early and proactively de-risk them to protect learner experience and commitments.
• Multiply your impact through mentoring senior engineers, influencing without authority, and stepping in hands-on when critical paths require it. 

You have:

• Extensive experience designing, building, and operating distributed systems using Typescript and AWS.
• Deep expertise in APIs, asynchronous systems, data modeling, and service-to-service communication in production environments.
• Strong architectural judgment and the ability to communicate trade-offs clearly in service of product and learner outcomes.
• Proven ability to improve system-level outcomes such as reliability, scalability, delivery speed, and operational excellence.
• Hands-on fluency with AI-assisted development tools and demonstrated integration of AI into daily engineering workflows.
• Experience experimenting with or building AI-powered systems, LLM integrations, or AI-enabled features.
• Pragmatic, metrics-driven judgment in evaluating where AI adds meaningful value versus where traditional approaches are superior.
• A track record of influencing technical direction across multiple teams without relying on formal authority.
• Strong product mindset with experience connecting technical decisions to experimentation and measurable customer impact.
• Demonstrated ability to mentor senior engineers, raise technical standards, and elevate AI fluency across an organization.

Nice to have:

• Experience with LLM evaluation frameworks, prompt engineering at scale, retrieval-augmented generation (RAG), or model experimentation pipelines.
• Experience building or scaling learning platforms, personalization systems, or A/B experimentation frameworks.
• Exposure to domain-driven design, event-driven architectures, or platform engineering.
• Experience shaping engineering operating models or standards during periods of technological transformation.
• Genuine interest in how AI, product, and learning science can combine to create meaningful learner outcomes.
• Experience with Golang.

Please note that our company’s operating language is English, so you will need to be able to work in English.

Some perks of becoming a Babbelonian:

• Enjoy 30 vacation days and the chance to take a 3-month Sabbatical. Plus family and life situation counseling.
• Decide how, when and from where you want to work with our flexible working hours and remote-friendly options as Jobbatical (up to 3 months inside the EU and UK) or work from our fully equipped office with nap, faith and family rooms. 
• Learn and grow with the internal learning opportunities, and use a yearly learning & development budget for external training. Learn languages with Babbel for free with your full access to Babbel & Babbel Live classes.
• Take advantage of your mobility benefits options and a discounted Urban Sports Club membership. 
• Be part of our employee communities (such as FLINTA, DE&I Ambassadors and LGBTQIA groups), attend cultural and regular social events. 

Diversity at Babbel

As part of our ongoing journey towards building a diverse, equitable and inclusive company, we welcome everyone to apply, especially those individuals who are underrepresented in tech. We are a learning company, inside and out, and we encourage you to apply even if you do not fit all the technical requirements - all candidates are assessed based on skills, qualifications and on our business needs. Please state your pronouns in your application, and let us know if you’d like to be addressed by a name other than the one appearing on your official documents. If you have a disability or special need, feel welcome to inform us, so that we can provide you with the proper assistance in the application process.