FERHAT SAYAN
Kalmar
Summary
Dynamic technology leader with a proven track record at DOCTOS, enhancing STT accuracy to 97% through advanced machine learning techniques. Skilled in Python and CI/CD practices, I excel in driving user engagement and retention while fostering team collaboration. Committed to delivering innovative solutions that achieve significant business growth.
Overview
10
10
years of professional experience
Work History
Sabbatical
(Career Break)
Kalmar
01.2025 - Current
- Upheld technical expertise via prototypes and small-scale open-source solutions; family/relocation.
Co-Founder & CTO
VEGAND.ME
Munich
01.2020 - Current
- Grew product to 14,000 registered users and 5,000 monthly active users via SEA, Instagram Ads, and influencer operations.
- Launched subscriptions with RevenueCat and experimentation with Firebase A/B testing; reached EUR 20,000 annual recurring revenue.
CTO (hands-on)
DOCTOS
Munich
09.2022 - 12.2024
- Raised STT accuracy from 85% to 97% by customizing Whisper and fine-tuning BERT in Python; reduced Word Error Rate from 15% to 3%.
- Rebuilt cross-platform app for iOS, Android, and Web (Flutter, Swift, Angular); modernized architecture and performance.
- Implemented CI/CD with GitHub Actions and Docker: 35% faster release cycle; standardized bi-weekly production cadence.
- Planned and tracked delivery with Jira (epics/stories); supported approximately 100 MAU across approximately 20 practices.
- Operated on AWS then migrated pipelines to Azure; services on Node.js with PostgreSQL.
Engineering Manager (hands-on)
TEAMSPORTS.AI
Berlin
01.2021 - 08.2022
- Increased user retention by 60% via targeted lifecycle messaging (Firebase Analytics and Cloud Messaging).
- Migrated Xamarin to Flutter, delivering approximately 4x faster UI and a unified codebase.
- Introduced peer code review and coding standards for a 7-engineer team; improved throughput by about 10%.
Head of Software Development & Software Developer
JUCONN & MINNT
Munich
01.2018 - 12.2020
- Built an IoT platform with gateway protocols (MQTT, OPC UA, LoRa/LoRaWAN) and a scalable MongoDB data layer.
- Achieved milestones that helped secure more than EUR 1,000,000 in funding; led a 3-person cross-functional team.
- Delivered features across Frontend (Angular) and Backend (NestJS, Node.js/Express, MongoDB).
Software Developer
MARPINION
Munich
09.2015 - 12.2018
- Doubled user retention by building a custom email-campaign engine integrated with Microsoft Dynamics CRM (C#/.NET + SQL Server).
- Improved content-team productivity by more than 50% via an Angular content-authoring tool.
- Contributed to the Xamarin mobile app and C#/.NET backend integrations; adhered to team code review practices.
Education
Vocational Diploma -
Stadtische Berufsschule fur Informationstechnik
Munich01.2013
Skills
- Python
- TypeScript
- JavaScript
- Dart
- C#
- Java
- SQL
- Flutter
- React Native
- Xamarin
- Swift
- Nodejs
- NestJS
- Express
- NET
- Web API
- WCF
- Spring Boot
- Angular
- PostgreSQL
- MongoDB
- Elasticsearch
- MQTT
- OPC UA
- LoRa and LoRaWAN
- AWS and Azure services
- Docker and containerization
- GitHub Actions and CI/CD
- Firebase and cloud messaging
- Analytics and A/B testing strategies
- RevenueCat integration
- Whisper and BERT models
Recognition
Apple App Store Foundations Program (EMEA), 2022, Invited based on app traction.
Languages
English
Proficient (C2)
C2
German
Native
Native
Swedish
Intermediate (B1)
B1
Timeline
Sabbatical
(Career Break)
01.2025 - Current
CTO (hands-on)
DOCTOS
09.2022 - 12.2024
Engineering Manager (hands-on)
TEAMSPORTS.AI
01.2021 - 08.2022
Co-Founder & CTO
VEGAND.ME
01.2020 - Current
Head of Software Development & Software Developer
JUCONN & MINNT
01.2018 - 12.2020
Software Developer
MARPINION
09.2015 - 12.2018
Vocational Diploma -
Stadtische Berufsschule fur Informationstechnik