Jakub Fronczyk
Software Engineer
Driven by curiosity and a need to understand the deeper mechanics of technology. I work across product engineering, cloud infrastructure, and software architecture, seeking out the challenges where the application meets the automated environment.
As AI changes the nature of coding, I focus on maintaining a deep understanding of the business logic within the system. Agents, strict TDD, type safety, staying in control of the final impact.
Work
Production systems I designed and shipped. Client platforms have no public URL, so only some of them link out.
CASSI
Core team · Full-Stack Engineer · architecture, generation pipeline, cloud infrastructure
AI content platform publishing to four social networks, each with its own auth, rate limits and media rules. Founding engineer; I owned the architecture.
Avantgard
Core team · Lead Engineer · architecture, rendering pipeline, service boundaries
Thousands of personalized letters rendered and posted per send. Lead engineer on the pipeline, the address-validation path, and the editor campaigns are built in.
Production Intelligence
Lead engineer · ontology, graph layer, retrieval, model serving
Manufacturing knowledge platform shipped per client, on-prem where data cannot leave the factory network. Lead engineer on the ontology, retrieval, and self-hosted model serving.
Order QR Tracker
Lead Engineer · offline sync, domain modelling, on-site delivery
Live part tracking replacing paper on a sheet-metal shop floor. Scans queue on the phone and reconcile when factory Wi-Fi drops out. Led two engineers.
GitHub
Things I build when I'm curious.
Most of what I build is client work or never gets a README — the rest is on my GitHub.
Experience
Teams I've shipped with.
Platform Engineering · Cloud Infrastructure · Software Architecture
Full-stack and platform engineering across product and cloud infrastructure. Service-oriented architecture in Python and TypeScript, with Go for the performance-critical paths, and AWS and Cloudflare managed as code in Terraform. Most of it moves the ML team's models from research into production, on managed cloud or fully on-prem.
AI Applications · Full-Stack · Cloud Infrastructure
Core team on an AI content platform, built on a type-safe TypeScript stack across Next.js, Bun and tRPC with PostgreSQL behind it, and AWS managed as code in Terraform with Docker and CI/CD. Took it from a VPC-isolated enterprise deployment to a public B2C SaaS, and built the layer where model output becomes product.
Product Engineering · SSR/SSG · Auth
Frontend engineering on a learning platform, built in Next.js and React with TypeScript. I turned the design system into a component library over server-rendered and static pages, and shipped the company's new site end to end with OAuth login, role-based access and subscription-gated routes.
Contact
Open to platform and infrastructure work, in Berlin or remote across the EU. Happy to talk either way.
jakubfronczyk@gmail.com