[gsid] backend engineering · zaandam, nl
NL EN

Backend systems/
that stay up.
PHP · Python · Go · Kubernetes.

operator gsid · Guido Smit
location Zaandam, NL
since 2007
status ● accepting new work
projects

· kdef.dev
· timepickr.net
· middleblock
· ceems
$ cat about.md
// 02

Backend engineering that survives Monday morning.

gsid is a backend developer based in Zaandam. I design, build, and operate services for products that need to keep working under real load — not just on the staging cluster.

Most engagements live in PHP (Symfony), Python, or Go, deployed on Kubernetes — most often RKE2 — on Linux/Debian. I take work end-to-end: from API contract, through implementation, to the running cluster and the runbooks the next engineer reads at 03:00.

Two things that have come out of the practice and are open to the public: kdef (declarative HCL for Kubernetes, open source) and Timepickr (an EU-hosted booking platform for service businesses).

$ ls -F services/
// 03
01
/usr/local/bin/build

Backend systems

  • API design & implementation (REST, GraphQL, gRPC)
  • Integrations & external systems
  • Symfony, Python and Go services
  • Tests, CI and observability from day one
02
/usr/local/bin/operate

Infrastructure & ops

  • Kubernetes / RKE2 cluster setup & lifecycle
  • Linux/Debian provisioning, hardening, backups
  • MySQL, Redis operation
  • Monitoring with Prometheus, Grafana, Loki
  • Domainregistrations, DNS management, E-mail hosting and web hosting
03
/usr/local/bin/rescue

Migrations & Optimalisations

  • Performance work on existing systems
  • Symfony major-version upgrades
  • Lift-and-shift to Kubernetes / RKE2
  • Documentation for whoever inherits it
$ stack --list
// 04
languages
PHP 8.x · Python 3.x · Go 1.2x · TypeScript (occasional)
frameworks
Symfony · Doctrine
orchestration
Kubernetes · RKE2 · Helm · Argo CD · Flux · kdef
data
MySQL / MariaDB· PostgreSQL · Redis · S3-compatible
runtime
Linux / Debian · Docker · nginx · Traefik · HAProxy
observability
Prometheus · Grafana · Loki · OpenTelemetry · Sentry
tooling
Git · GitHub Actions · Drone· VS Code
messaging
RabbitMQ · Reddis · Symfony Messenger · WhatsApp Cloud API
$ ls -la work/
// 05
drwxr-xr-x
2.4M
active
kdef
›
kdef — declarative HCL for Kubernetes. The syntax Terraform users already know, compiled to plain Kubernetes YAML. Typed variables, native loops, environment overrides, first-class sealed secrets. Open source, written in Go.
stack Go · HCL · Kubernetes API
role creator & maintainer
drwxr-xr-x
12.8M
live
timepickr
›
Timepickr — an EU-hosted booking & reservation platform for service businesses (restaurants, salons, clinics, hotels). Multi-tenant, multi-service, multi-location. WhatsApp / SMS / email reminders, deposits, vouchers, calendar integrations. GDPR-compliant.
stack PHP · Symfony · MySQL · RKE2
role design, build, operate
hosting EU only
drwxr-x---
8.2M
2024
ecommerce-platform
›
Dutch e-commerce platform · Symfony major-version upgrade, monolith decomposition into services on GCloud. Throughput up ~4×, infra cost down ~30%. Under NDA.
stack Symfony · GCloud · Redis
duration 9 mo
role lead backend & infra
drwxr-x---

3.6M
2023
data-pipeline
›
Python ETL pipeline for a logistics operator · processing ~12M events/day from heterogeneous sources, materialised into a MySQL warehouse with backfill and replay. Deployed as cron-driven jobs on Kubernetes. Under NDA.
stack Python · MySQL · K8s · NATS
duration 5 mo
role sole engineer
$ mail info@gsid.nl
// 06