Hello, I’m Cafer Şimşek.

I build things that work. And I like knowing why.

I’ve been writing code since 1997. These days, I work across software engineering, infrastructure, cloud, networking, and security — still happiest when I’m close to the details.

Explore my workA little about me

  1. curiosity1997
  2. basic → clate ’90s
  3. applications
  4. apis · databases
  5. networks · cloud
  6. platforms · security · pki
  7. cafer.tryou are here

29 years of finding out how things work.

My journey started with BASIC and C in the late ’90s. Over the years, the work expanded from writing applications to designing the systems they depend on: APIs, databases, networks, platforms, and security infrastructure.

I’ve taken on leadership responsibilities along the way, but I never stopped enjoying the hands-on work.

More about me

Black-and-white portrait of Cafer Şimşek inside a dark red ring that reads “CONN REFUSED”.
Connection refused.
Conversation welcome.

Things I’ve been building.

Small, sharp tools that live on the edge, and a larger platform in progress.

  1. 01live

    ipne.me

    A fast IP and network lookup that answers browsers with a clean page and curl with plain text.

    • TypeScript
    • Cloudflare Workers
    • RDAP
    • DNS over HTTPS

    ipne.me

  2. 02live

    cfb.sh

    A developer toolbox on the edge — the small utilities I reach for every day, one hostname away.

    • TypeScript
    • Cloudflare Workers
    • POSIX shell

    cfb.sh

  3. 03in development

    VLMarket

    A multi-tenant marketplace where game and platform companies let their users trade virtual items safely, for real money.

    • Java
    • Spring Boot
    • PostgreSQL
    • React
    • TypeScript
    • Playwright

Project detailsMore on GitHub

Where I spend my time.

The layers I work across, from the code down to the wire. Topic areas, not a trophy shelf.

Software
  • Go
  • Java & Spring Boot
  • Python
  • TypeScript
  • API and service design
Platforms
  • Linux
  • Containers & Kubernetes
  • Infrastructure as code
DevOps & SRE
  • CI/CD
  • GitOps
  • Observability
  • SLOs & error budgets
  • Incident response
  • Postmortems
Cloud & networking
  • AWS
  • Oracle Cloud (OCI)
  • Load balancing
  • VPN architecture
  • Cloudflare Workers
Security & trust
  • PKI & X.509
  • TLS
  • TPM & PKCS#11
  • Certificate lifecycle
  • Applied cryptography
Data
  • PostgreSQL
  • MySQL
  • Performance
  • Operational reliability

  1. Understand the system, not just the interface.

    Abstractions are wonderful until they leak. Knowing what sits underneath is what turns a long outage into a short one.

  2. Complexity should justify its existence.

    Every moving part is something to run, secure, and explain at 3 a.m. The simplest design that does the job usually wins.

  3. Stay hands-on. Keep learning.

    The tools change every few years. Reading the code, the RFC, or the packet capture never goes out of style.

Say hello.

Questions about something I’ve built, an interesting problem, or just shop talk: my inbox is open.

cafer@cafer.net

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