Demircan Celebi
Software engineer in London. Building software since 2009. Alive since 1993.
Projects
2020Litafl & tafl
Viking chess (hnefatafl) playable online, plus its open-source engine.
2019Asonans
Finds assonance in Turkish text.
Posts
2026My MacBook can’t divide by 20
An Apple Metal compiler bug that made 0 / 20 equal 25, and what the GPU was actually doing.
2014How I hacked PayPal to create money
Found where PayPal’s fee rules contradicted themselves. Filed a bug ticket instead of writing the script.
2014Stayin’ Alive
Optimal play in two-bullet Russian roulette, then a tool to explore every variant.
Past work
2023 – 2026Erguvan
Cofounder & CTO
Built KPI tracking and reporting software used by banks and other large organizations.
Also built Türkiye’s official sustainability disclosure platform as a side quest.
2020 – 2023OakNorth
Software engineer
Data pipelines feeding credit decisioning and portfolio tools, plus code generation that cut weeks off adding a new data source.
2018 – 2019Oliver Wyman
Software engineer
Financial modelling software that compressed months of model-building into days.
2011 – 2018Earlier
Software engineer, founder
Cofounded Marketinf (marketplace-builder SaaS; raised investment).
Built a chatbot platform deployed to a ~20,000-employee portal at a global security firm.
Freelance web & mobile for clients including WWF and Sodexo.
Front-end developer (employee #2) at Metrekare.com; earlier front-end work at three Istanbul digital agencies.
Education
2011 – 2017Boğaziçi University
Double major
Management Information Systems and Tourism Administration.