{ }
work
stack
writing
now
◉ Berlin → Remote
● Available Q3 2026
12+ yrs shipping
PRINCIPAL · DISTRIBUTED SYSTEMS
Principal engineer focused on resilient distributed systems and the developer platforms teams actually want to use. I've spent a decade shipping the unglamorous infrastructure — schedulers, message buses, build systems, internal SDKs — that make product engineers fast.
in production
req/day at peak
% SLA shipped
OSS maintained
~/kael — zsh
$ whoami
principal_engineer
$ ls ~/focus/
distributed-systems/ developer-platforms/
observability/ api-design/
$ cat ./principles.txt
→ boring tech compounds
→ failure modes > happy paths
→ a good abstraction earns its weight
$ █
CURRENTLY SHIPPING
a multi-tenant scheduler in Rust.
// 01 — PHILOSOPHY
The best engineering work I've seen looks unremarkable from the outside. A queue that drains. A deploy that doesn't wake anyone up. A migration that finishes with three engineers still asleep on a different continent. That's the bar I aim for — systems that get out of their own way.
I lean boring on stack choices and weird on internal abstractions. I trust observability over hunches, prefer simulation over reactive debugging, and treat documentation as infrastructure. Most of all, I optimize for the engineer who'll inherit this in two years — usually a version of me who's forgotten most of it.
distributed systems
platform engineering
observability
API design
technical leadership
// 02 — STACK & TOOLING
Not a checklist. These are the ones I'd defend in a design review at 4pm on a Friday.
⟨/⟩
Rust for systems work where memory and latency budgets matter. Go for services. TypeScript for everything customers touch. Python when the data wants to talk back.
Rust
Go
TypeScript
Python
Elixir
◈
Kubernetes when it earns its place, raw EC2/Fly when it doesn't. Terraform for the boring stuff. Pulumi when I want types. Postgres until proven otherwise.
Kubernetes
Terraform
AWS
Postgres
Pulumi
✦
Kafka for the high-throughput stuff, NATS when latency wins. ClickHouse for analytics that need to feel instant. Temporal for workflows that absolutely cannot drop.
Kafka
NATS
ClickHouse
Temporal
Redis
◐
OpenTelemetry everywhere. Prometheus + Grafana for the dashboards engineers actually use. Tempo for traces. Honeycomb when the question matters more than the metric.
OpenTelemetry
Prometheus
Grafana
Honeycomb
// 03 — SELECTED WORK
Three projects that taught me the most about systems, teams, and the gap between what spec docs say and what production demands.
PROJECT 01
OPEN SOURCE
Multi-tenant workload scheduler · Rust
A bin-packing scheduler that hands out compute across noisy-neighbor-prone tenants without dropping latency budgets. Wrote the constraint solver, the gossip-based membership layer, and the admission controller. Now scheduling ~3.2M jobs/day in production.
p99 < 4ms
Admission decision
3.2M/day
Jobs scheduled
2.1k★
GitHub stars
// scheduler/admission.rs
pub fn admit(req: &Request) -> Decision {
let budget = self.tenant.budget();
if budget.would_exceed(req) {
return Decision::Defer(backoff);
}
self.solver.place(req).into()
}
[ARCHITECTURE]
edge →
ingest
→
kafka
→
stream-proc
↓
clickhouse
←
materializer
→
dashboards
→ p95 query latency dropped from 8.2s to 340ms
PROJECT 02
INTERNAL
Real-time telemetry pipeline · Go + ClickHouse
Replaced a creaking Elastic stack with an OpenTelemetry-native pipeline. 47B events/day, sub-second query latency on the dashboards engineers actually open at 3am. Cut infra cost by 64% along the way.
Go
ClickHouse
Kafka
OTel
PROJECT 03
PLATFORM
Internal developer platform · TypeScript + K8s
The deploy tool 220 engineers use every day. Built on Kubernetes, Argo, and a thin TypeScript control plane. Median time-to-prod went from 47 minutes to 6. Most importantly, on-call pages from broken deploys dropped 71%.
→
Atomic rollouts with automatic rollback on SLO breach
→
Service catalog + ownership routing for incidents
→
Cost dashboards engineers can read without a PhD
BEFORE / AFTER
Median deploy
47 min → 6 min
−87%
On-call pages
21/wk → 6/wk
−71%
Eng adoption
0 → 220 engs
100%
// 04 — EXPERIENCE
Twelve years across infra teams, platform orgs, and the occasional startup — building the stuff product engineers stand on.
2023
—
now
Principal Engineer · Platform
·
REMOTE
Tech lead for the platform group (~30 engineers). Drove the org-wide migration from monolithic deploys to a service-mesh-backed platform. Designed the SLO program, wrote the RFC process, and rebuilt the on-call rotation around alert quality, not alert volume.
Platform Engineering
RFC Process
SLO Program
Tech Leadership
2019
—
2023
Staff Engineer · Infrastructure
·
BERLIN
Rebuilt the global payments backend during hypergrowth. Designed the idempotency layer that survived a 50× traffic spike on a Black Friday I'd rather not relive. Mentored 4 engineers from senior to staff, including one who now runs the team.
Payments Infra
Idempotency
Mentorship
2016
—
2019
Senior SWE · Backend
·
AMSTERDAM
Owned the API gateway and ingestion pipeline. Migrated us from a fragile monolith to Go microservices over 18 months — and somehow nobody noticed in prod. Also wrote way too many bash scripts.
API Gateway
Microservices
Migrations
2014
—
2016
Software Engineer · First hire
·
STARTUP
Wore every hat. Built the first version of the product, the deploy pipeline, the on-call schedule, and the awful interview rubric I'd later spend years apologizing for. Acquired in 2016.
Full-stack
0→1
Acquired
// 05 — IMPACT
Selected metrics from the past five years. Happy to walk through how I got each of them — including the ones I'd do differently now.
REQUESTS / DAY
Peak load handled by the telemetry pipeline I designed at Helios.
SLA SHIPPED
Three years running on the payments backend at Cordoba. Two near-misses, zero region-wide outages.
INFRA SPEND
Replaced the Elastic stack with ClickHouse. Saved ~$2.1M/yr without losing query power.
ENGS ON PLATFORM
Every engineer at Helios uses the platform I built. NPS held at +52 through two re-orgs.
WORK I'M MOST PROUD OF
Spent a year killing every flaky alert and rewriting runbooks around symptoms instead of metrics. Net result: pages dropped 71%, MTTR halved, and one engineer told me on-call "finally feels respectful." Most underrated thing I've shipped.
−71%
FEWER PAGES
// 06 — OPEN SOURCE
Some I started, some I just keep alive. All of them I'd happily talk you through.
kael/helix
★ 2.1k
Multi-tenant scheduler in Rust. The project from the case study above, now run by a small community of contributors.
Rust
Apache-2.0
kael/otel-sketch
★ 890
OpenTelemetry processor that samples on cardinality, not just rate. Used by a handful of mid-size SaaS companies in prod.
Go
MIT
kael/cargo-explain
★ 1.4k
A cargo subcommand that explains compiler errors in plain English. Started as a weekend joke; now a real tool. Featured in This Week in Rust.
Rust
MIT
// 07 — WRITING & TALKS
Essays and conference talks on distributed systems, platform engineering, and the boring discipline of running production.
ESSAY · 2026
How we rebuilt the rotation at Helios around symptom-based alerting and finally got engineers to volunteer for shifts.
TALK · KUBECON '25
A war story about default kube-scheduler behavior under multi-tenant load — and what we built instead.
ESSAY · 2025
Why I budget docs work alongside services, with the same SLOs, and what changed when we did.
TALK · SREcon '24
A walkthrough of the Black Friday that almost broke our payment system — and the design we'd ship today.
// 08 — CREDENTIALS
M
ETH Zürich
2012 — 2014
B
TU Delft
2009 — 2012
★
Professional · current
RENEWED 2025
◇
MIT CSAIL · advanced topics
2023
// 09 — KIND WORDS
Pulled from references and Slack DMs I asked permission to quote. Happy to put you in touch with any of them.
"
Kael writes designs the way most people wish docs read: tight, honest about tradeoffs, and never trying to sound smart. I learned more reading his RFCs than I did in two grad classes.
MO
Marcelo Ortega
Director of Eng · Helios
"
He's the engineer I want around when something is on fire AND when nothing is. Calm during incidents, relentless during planning. Took our infra from rumor-driven to actually instrumented.
PV
Priya Venkat
VP Infrastructure · Cordoba
"
Kael mentored me into staff. Not by being nice — by being honest. He gave me the kind of feedback I couldn't have gotten anywhere else, and the trust to act on it.
JK
Jonas Kessler
Staff Engineer · Cordoba
// 10 — NOW
Updated whenever something changes. Inspired by /now pages everywhere.
BUILDING
A multi-tenant scheduler in Rust that doesn't make me hate noisy neighbors.
READING
Designing Data-Intensive Applications (again), and the Tigerbeetle design docs.
ADVISING
Two infra startups (seed + Series A) on platform direction and hiring.
AWAY FROM
Kubernetes operators. I love them. I need a break.
// 11 — CONTACT
Open to senior IC roles, tech-lead positions, and selective fractional engagements with infra or platform teams. I'll respond to anything that isn't a recruiter blast.
$
© 2026 Kael Voss · Berlin
designed in vim · deployed on a tuesday