# Curriculum vitae / Lauri Tirkkonen

## Contact

 * <lauri@hacktheplanet.fi>
 * lotheac @ IRCnet, libera.chat, and oftc

## Languages

 * Native Finnish
 * Fluent English
 * Intermediate Japanese

## Education

 * 2008 – 2016: M.Sc. (Tech), Computer Science and Engineering at Aalto
   University School of Science (form. Helsinki University of Technology)

## Work

 * Freelance\
   2024-11 – present: SRE/DevOps/SWE Consultant

 * PayPay株式会社, Tokyo, Japan\
   2022-04 – 2024-11: SRE Tech Lead

   * Division-wide migration from New Relic to self-hosted metrics, alerting
     and tracing system based on Victoria Metrics, Grafana, OpenTelemetry and
     ClickHouse. Increased metrics resolution by 6x and improved trace
     reliability, while reducing yearly cost by 80%
   * Maintenance and redesign of logging pipelines. Reduced the number of lost
     logs to zero, and made the entire system significantly cheaper by
     simplifying its architecture

 * iconicchain Oy\
   2021-01 – 2022-03: Head of DevOps and Security

   * Building infrastructure (Hetzner cloud), supporting development (eg.
     creating tools to run dev workloads in hcloud), optimizing deliveries and
     Docker image builds, building CI/CD & improving test performance

 * Siili One Oy\
   2019-12 – 2020-12: Staff SRE

   * Consultant; technical lead on an embedded Linux system project for a
     customer in the telecommunications industry

 * Tuxera Inc.\
   2017-04 – 2019-12: Release Engineer

   * Development and maintenance of online build service used by customers,
     400k–600k kernel module builds delivered per year

 * Aalto University Department of Computer Science and Engineering\
   2009-05 – 2011-05, 2011-09 – 2017-03: Systems Designer

     * Unix (Solaris, illumos, Linux, OpenBSD) server and workstation
       administration. Xen and KVM virtualization, illumos zones (containers)
     * Building and upgrading internal systems, migrating from legacy
       solutions. Examples:

         * LDAP authentication and name services
         * Puppet configuration management for workstations and servers
         * Redundant firewalls with pfsync and CARP

     * Improving processes and workflows, eg. putting everything under version
       control, deploying an issue tracker

## Skills / experience

 * Operating systems

     * Various GNU/Linux distributions (Debian, Ubuntu, RHEL, CentOS, Alpine,
       Void… you name it)
     * OpenBSD
     * illumos, Solaris 10, 11, OpenSolaris

 * Programming language preferences: Zig, Python, C (C99), shell
 * Instrumentation and debugging

     * bpftrace, DTrace, traditional debuggers like gdb, mdb
     * traditional Unix visibility tools (strace, ps, netstat,
       vmstat, fstat, etc.)

 * TCP/IP networks in depth, including IPv6
 * Network security: firewalls (pf, nftables, iptables), SSL/TLS,
   ZTNA (Tailscale, headscale)
 * IAM: SSO (OIDC, SAML); Keycloak, Authentik, FreeIPA, LDAP etc.
 * Storage: ZFS (incl. send/receive based backup systems)
 * Containers: systemd-nspawn, podman, Docker, Solaris zones
 * Orchestration: Kubernetes (kubeadm, bare-metal, kOps, EKS, k3s)

   * [Kubestronaut](https://www.credly.com/badges/a811de3d-7a3e-4825-b4d0-65681867cc94/public_url)

 * Configuration management: Ansible, Puppet, Terraform
 * Observability: Victoria Metrics, Prometheus, Grafana, OpenTelemetry,
   New Relic
 * CI/CD: git, Jenkins, GitHub Actions, GitLab, sr.ht
 * Build systems: OpenEmbedded/Yocto, Android, GNU make, BSD make, CMake,
   Meson, GNU autotools
 * Porting, packaging, patching and contributing to open source software

## Other

 * Worked on a [hobby operating system](https://unleashed.31bits.net/) from
   2016 to 2019