Mobile banking backend · 2021
Rebuilt the account ledger and sync API behind an Istanbul payments app.
Balance updates under 1 s · 1.2M accounts migrated · 0 lost transactions
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Backend PlatformEngineer
I design the services, queues and deploy pipelines behind products people use every day, then keep them running at 3 a.m. so nobody else has to.
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Internal developer platform · 2023
A preview environment for every pull request at Havenlijn, plus a deploy path anyone can read.
Deploys 40 min → 6 min · Staging queue gone · First deploy in week one
POST /v2/berths/RTM-07/holds
{
"vessel": "9241378",
"window": ["06:00", "14:00"],
"expires_in": 900
}
201 Created · hold confirmed in 15 minPublic API · 2024
The API shipping agents use to book quay time at Havenlijn's terminals.
99.98% uptime over two years · 41 integrators · No double bookings since launch
~/svc $ cargo add sluice
Adding sluice v1.4.2
~/svc $ cargo bench check
check/allow 38.1 ns ±0.4
check/deny 37.6 ns ±0.3
~/svc $ Open-source Rust library · 2022
A small rate limiter for Rust services; one dependency, no background threads.
2.1k GitHub stars · 38 ns per check · Maasstad Open Source Prize 2024
Performance audit · 2025
Two-week search audit for an independent bookshop's online store.
p95 380 ms → 45 ms · Typo searches find results · Two-week fixed price
31 → 4
pages per week
Alerting rewrite · 2023
Cut Havenlijn's weekly pages from 31 to 4 by alerting on symptoms users feel.
31 → 4 pages a week · 140 rules → 12 · Runbook on every alert
Twelve years of it, with dates and numbers, fits on two pages.
Read the CV<!-- About me -->
Under the hood
I'm a backend engineer who cares about the boring parts: migrations, retries, alerts and the documentation nobody asked for. Those are the parts that decide whether a product still works on its worst day.
Right now I'm a staff engineer at Havenlijn, where our software schedules trucks and ships through the port of Rotterdam. Before that I spent four years on payments in Istanbul. I review code like I'd want mine reviewed: short, specific, with a link.
Download CV
<!-- Previous builds -->
- 2022 – nowStaff Software EngineerHavenlijn
- 2018 – 2022Senior Backend EngineerLodos Pay
- 2015 – 2018Software EngineerKademuur Software
- 2014 – 2015Junior DeveloperStudio Kwelder
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1. Backend & APIs
- Go and Rust services
- REST and gRPC API design
- Postgres schemas and migrations
- Queues with Kafka and NATS
- Idempotent payment flows
- API docs people actually read
2. Platform & infrastructure
- Kubernetes without the ceremony
- Terraform for every environment
- CI pipelines under ten minutes
- Preview environments per pull request
- Tracing with OpenTelemetry
- Cloud bill reviews
3. Team & practice
- Code review that teaches
- Blameless incident reviews
- Mentoring mid-level engineers
- Architecture decision records
- Hiring loops and design interviews
- Writing it down
<!-- My tech stack -->
- Go9 yrs
- Rust4 yrs
- PostgreSQL11 yrs
- TypeScript7 yrs
- Kubernetes6 yrs
- Terraform5 yrs
- Kafka4 yrs
- Python10 yrs
- Linux12 yrs
- Grafana5 yrs
- Neovim8 yrs
- Redis8 yrs
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Industry recognition
- Maasstad Open Source Prize2024
- Speaker, Polderdev Conference2023
- Speaker, Lijnbaan Tech Nights2022
- Speaker, Kralingen Rust evening2021
Team recognition
- Havenlijn Engineer of the Year2023
- Lodos Pay hack week winner2020
- Zero-downtime migration award2021
<!-- Colleagues' word -->
What people
say after
Elias rewrote our deploy pipeline in six weeks, then spent two more teaching us how it works. We still use his runbook.
Marieke de Vos, VP Engineering, HavenlijnHe asked for the failure cases before the happy path. That is why the migration went quietly.
Deniz Arslan, CTO, Lodos PayThe best code reviews I've had. Short, specific, and always one link to read.
Joost Hendriks, Software Engineer, HavenlijnWe booked him for a two-week audit. He found the slow query on day one and spent the rest making sure it stayed fast.
Anne Linde, Owner, Boekhuis LindeWhen the queue backed up at 3 a.m., his messages in the channel were the reason nobody panicked.
Selin Kaya, SRE Lead, Lodos Pay
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From my notes.md
The boring migration: 1.2M accounts, no maintenance window
Preview environments cost less than the meetings they replace
New notes once a month, by email.
Get notes by email<!-- Get in touch -->
Let's build it together
Contract work from January, or a full-time platform role. Tell me what's breaking.