You develop and extend Logos, our platform for complex legal and regulatory processes that has been running in production for over 20 years – in Common Lisp (SBCL), with a REPL-centric workflow and modern tooling (ASDF, SLIME/SLY)
You own core logic, HTTP endpoints, and services, ensuring the platform remains maintainable, extensible, and future-proof
You work with PostgreSQL on schema evolution, migrations, and query optimisation – using hu.dwim.perec and custom SQL tooling
You maintain and evolve XML/XSLT pipelines (cxml, plexippus-xpath, libxslt) as well as document generation (cl-pdf, OOXML)
You contribute to HTTP/web components (Hunchentoot), Auth/SSO, and mail integration
You drive the platform's SaaS readiness: reproducible builds, containerised configuration, and observability (logging, metrics, tracing)
You leverage AI-assisted development tools to safely analyse and evolve large Lisp codebases
You actively contribute to engineering excellence: tests, CI, code reviews, and documented architectural decisions

Several years of hands-on experience with Common Lisp in production – you are confident with CLOS, macros, conditions/restarts, and a REPL-first workflow
Solid PostgreSQL skills: schema design, indexing, tuning, and migrations are part of your day-to-day work
Experience with XML/XSLT and common Lisp libraries (including alexandria, bordeaux-threads, cl-ppcre, drakma, cffi)
You can modernise legacy systems incrementally without destroying proven, valuable foundations
Nice to have: experience with hu.dwim.perec, Postmodern, or cl-dbi
Nice to have: Python skills for integration with our Rulemapping Automation and AI service landscape
Nice to have: Linux server operations, container workflows, Nix/NixOS
You communicate clearly and concisely in English; German is a plus

You work on a technically demanding, production Lisp codebase with a real societal mission – not a greenfield toy project, but over 20 years of meaningful, accumulated substance
You actively shape how an established platform becomes fit for the next decade
Flexible working model: full-time with the option to work predominantly remotely – with a modern office in Berlin-Mitte for the days when being in the room matters
A small, technically strong team with short decision-making cycles
Innovative projects at the intersection of Legal Tech, AI, and regulatory automation

Senior Lisp Developer (m/w/d)