Senior Full-stack Engineer - AI

Wiser Technology designs, builds, and scales complex software systems that power real-world impact. With 500+ engineers and over 25 years of experience in mission-critical environments, we help global organizations turn ambitious ideas into working solutions. Across Europe, MENA, and North America, we combine deep engineering expertise with AI and data to support leading companies in aerospace & defense, automotive, telecom & media, IT, and financial services.

We are looking for a Senior Full-stack Engineer to join our team building and running high-profile, next-generation AI platforms for executive and strategic clients. You will anchor the AI-heavy Python backend, turning LLM capabilities into dependable services, and independently build the React/Next.js frontends your features need. This is a high-autonomy role with real ownership: you take features from design to production, shape technical design within established architectures, and keep live systems reliable.

Depending on the engagement, you will either help build new capabilities on an AI platform under active development, or join a dedicated managed-support team that keeps live AI platforms stable, secure and improving after go-live.

Core Responsibilities:

• End-to-End Delivery: Design, build and ship production-ready, well-tested features across a Python backend and React/Next.js frontends.
• AI Integration: Turn LLM capabilities, including retrieval over clients' own content, into dependable product features.
• Integrations & Data: Connect AI services with enterprise systems and data sources through stable, documented interfaces, and own the data models behind your features.
• Reliability: Build services that stay predictable under load and when the systems they depend on misbehave.
• Security: Implement authentication, authorization and data protection in line with demanding client security standards.
• Production Operations: Make your services observable, investigate and resolve production issues, and keep client stakeholders informed with clear status updates and root-cause write-ups.
• DevOps & Infra: Containerize your services and own their delivery pipelines, working with DevOps on deployments and production readiness.

Hard Requirements:

• 7+ years of backend-heavy or full-stack software engineering experience.
• Deep, production-level Python backend experience (e.g. FastAPI), including API design, API security and strong SQL.
• Production experience with React and TypeScript (Next.js preferred), enough to build and maintain the UI your features need on your own.
• You have taken LLM-powered features into production for real users, beyond prototypes and tutorials, and kept them working after launch.
• You have built and run services that depend on other systems, and seen production incidents through from first alert to a lasting fix.
• You thrive in fast-moving environments, learn new tools quickly, and communicate clearly in English with technical and business stakeholders.

Preferred:

• Hands-on experience with Microsoft Azure, especially its AI services.
• Experience running containerized services on Kubernetes in production.
• Experience orchestrating multi-agent LLM systems (LangChain / Microsoft Agent Framework / similar).
• Comfort working across polyglot codebases (e.g. Node.js or .NET services), including code you didn't write.
• Experience in regulated industries such as financial services, or delivering highly compliant enterprise or public-sector software.

WHAT’S IN IT FOR YOU

Culture & Development:

• Friendly Environment: We take pride in our culture, and we love spending time together.
• Team Spirit: Be part of a supportive team that uplifts each other.
• Mentorship and coaching. Our colleagues are experts in their field, and you can expect to have a strong team to rely on.
• Personalized Development Program: We realize one size doesn't fit all, so you get an individual development plan tailored specifically to your career aspirations.

Social Benefits:

• A Suite of Perks: Additional health insurance, referral bonus, and more.
• Work Flexibility: Embrace flexible working hours and a hybrid work model.
• Multiple Office Locations: in Sofia, Plovdiv, Stara Zagora, and Nis, you choose where you would like to work.
• Community and Connections: Engage in exciting social events and team initiatives.

Wiser, We Have The Code®