Deniz Arcan

01About

I build the unglamorous parts of software — billing, permissions, offline sync — and make them feel obvious to the people who use them. Ten years across product teams of four to forty, mostly TypeScript and Postgres.

Right now: pricing and permissions at Tilda Ledger. Before that, freight software that had to work in tunnels.

02Experience

1. Current step
   Senior product engineer · Tilda LedgerMar 2023 – present · 3 yrs 9 mos

   B2B invoicing, 2,400 business customers · Istanbul · hybrid

   • Led the move from per-seat to usage-based pricing: 2,400 accounts migrated over six weeks with zero incorrect invoices.
   • Designed the role and permission model now used by every product team; access-related tickets fell from 140 to 31 a month.
   • Mentor two engineers; run the fortnightly RFC review.

   TypeScript / React / Node.js / Postgres / Temporal

2. Completed
   Product engineer · YükportJun 2020 – Feb 2023 · 2 yrs 9 mos

   Freight marketplace for regional hauliers · Istanbul

   • Built the offline-first driver app (React Native); proof-of-delivery works with no signal and syncs within 4 s of reconnecting.
   • Cut support calls from drivers by 38% by replacing a 9-step job flow with three screens.

   React Native / SQLite / Go / Kafka

3. Completed
   Frontend engineer · Mavna StudioJan 2018 – May 2020 · 2 yrs 5 mos

   Product studio, 14 people · Izmir

   • Shipped 11 client products, from a ferry ticketing kiosk to a municipal open-data portal.
   • Started the studio’s shared component library and accessibility checklist.

   React / TypeScript / GraphQL

4. Completed
   Software developer · Sema YazılımJul 2016 – Dec 2017 · 1 yr 6 mos

   ERP integrations · Ankara

   • Wrote the e-invoice export used by 300 accounting offices.

   C# / SQL Server

03Selected projects

• 2025Usage-based billing without a big bangA shadow-invoicing system ran the new prices beside the old ones for two billing cycles, so every customer saw their new bill a month before paying it.0 incorrect invoices · churn flat at 1.1%PostgresTemporalProduct
• 2024Permissions people can readA permission editor that answers “what can this person do?” in plain sentences, with a preview of the app as that person.Access tickets −78%ReactDesign systems
• 2022Proof of delivery, offlineA small sync engine on SQLite with per-field conflict rules, so a driver in a tunnel never loses a signature.Sync p95 3.8 s · 0 lost deliveries in 14 monthsReact NativeSQLite
• 2021–is-gunu — Turkish business daysAn open-source TypeScript library for Turkish public holidays, half days and business-day maths. 1.2 kB, no dependencies.1,240 stars · 38k weekly downloadsOpen sourceTypeScript

04Writing and talks

• 18 Sept 2026Shadow invoices: how we changed every price without a single angry email11 min read
• 2 Apr 2026Write the permission sentence first6 min read
• 20 Nov 2025Offline-first is a product decision, not a library9 min read
• 7 Jun 2025The RFC template we actually use4 min read

• 9 Oct 2026Talk · “Shadow invoices”, Product Night Kadıköy #48
• 13 May 2023Talk · “Sync in a tunnel”, Field Apps Day, Izmir

05Skills

Languages

TypeScript, SQL, Go; enough Rust to review it

Frontend

React, React Native, accessibility (WCAG 2.2), design systems

Backend

Postgres, durable workflows, queues, billing and tax rules

Ways of working

Short RFCs, pairing with design, owning on-call for what I ship

Spoken languages

Turkish (native), English (C2, daily at work), German (B1)

Education

BSc Computer Engineering, Anadolu Technical University, Ankara, 2012–2016. Thesis: conflict-free replicated data for field apps.

06Contact

Hiring for a team that owns something hard? Write to me — I reply within a day.

Email

deniz@example.com

Phone

+90 216 000 00 00 · weekdays 10:00–18:00 (GMT+3)

CV

Download PDFOpens the print dialog; choose “Save as PDF”.