Ahmet Tufan Helvaci.

Hi, and welcome! I’m Tufan, a software engineer living in Amsterdam. This is my little corner of the internet, where I keep the things I make, learn and love. Stay a while and have a look around.

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About me

I love software development, and Java is the language I call home.

I’m Ahmet Tufan Helvaci, Tufan for short. I’m from Türkiye, spent the first years of my career in Istanbul and moved to Amsterdam in 2021.

I’ve been writing software for nine-plus years, and I still enjoy it as much as on day one. Java is my main language, and I like working across the stack, from the backend to the screen people actually see.

Today I’m at ABN AMRO. Before that I worked at Daimler, N11.com, Accenture and Credit Europe Bank, and I learned something from every one of those teams.

Away from the keyboard you’ll find me on a road bike, on a tennis court or somewhere with a heavy bassline. This site is where the rest of my curiosity goes: projects, notes and experiments.

Poke around the projects, read the blog or just say hi.

Patch notes v2020 to v2026

Added: Moved from Istanbul to Amsterdam (2021)
Added: Finished the MSc in Software Engineering at Boğaziçi (2022)
Added: Grew from four years of experience to nine-plus
Added: Started leading developers, not just writing code
Added: Migrated AngularJS to Vue.js, Oracle to PostgreSQL, on-prem to Azure
Removed: Backend-only Java developer
Removed: Master’s student
Unchanged: Still here: Java, sci-fi and a long reading list

On my shelf

Effective Java Joshua Bloch
Grokking Algorithms Aditya Bhargava
Sapiens Yuval Noah Harari

On my screen

Away from the keyboard

Road cycling
Tennis
Techno
Travel

Experience

Where I have worked, newest first.

you are here

ABN AMRO Bank

Senior full-stack Java developer, IFRS-9 regulatory reporting

Aug 2021 to present, Amsterdam
- Cut a critical monthly batch run from ~~7 hours~~ to under 45 minutes.
- Raised test coverage from ~~15%~~ to 80% across three applications.
- Rebuilt the team’s front end from AngularJS in Vue.js, using the bank’s Emerald design library.
- Helped move from Oracle to PostgreSQL, and three Java apps from on-prem to Azure with CI/CD, AKS and Bicep.
- Lead developers in the team, mentor newer colleagues and take part in technical hiring.
- Java 17/21
- Spring Boot
- Spring Batch
- Vue.js
- PostgreSQL
- Azure
- Kubernetes
- Bicep
Mercedes (Daimler)

Backend developer

Nov 2020 to Jul 2021, Istanbul
- Designed REST API endpoints and shipped new features in Java and Spring.
- Java
- Spring
- REST
N11.com

Backend Java developer

Jul 2019 to Nov 2020, Istanbul
- Worked on payment integrations for an e-commerce marketplace: fixed critical bugs and tuned performance.
- Built REST APIs serving web, Android and iOS clients, backed by unit and integration tests.
- Java
- Spring
- Hibernate
- JUnit
- Mockito
Accenture

Full-stack developer

Apr 2018 to Jul 2019, Istanbul
- Consulted on insurance platforms for policy creation and claims processing, used by agencies, banks and brokers.
- Ran bi-weekly knowledge-sharing sessions on smart-contract trends for the Blockchain R&D initiative.
- Java
- Spring
- JSF
- HTML
Credit Europe Bank

Blockchain R&D intern

2017, Amsterdam
- Researched blockchain and wrote Solidity smart contracts on Ethereum.
- Solidity
- Ethereum