Looking for a job

Fred Wang

@fredwang

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Senior backend engineer at Klar and Monta who owned Kotlin services for banking transactions and billing.

Germany

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What I'm looking for

I'm looking for senior backend roles where I can own production-critical systems and mentor strong engineering teams.

At Klar, I owned Kotlin backend services across transactions, lending, and notifications as the neobank grew past 1M users. I also built Kafka-based event-driven systems for real-time experimentation and data collection.

At Monta, I owned billing and invoice-generation pipelines for its EV charging platform, and migrated selected legacy PHP services to Kotlin microservices. I collaborated with the Data Science team on reporting and analytics pipelines.

Earlier, I built services and APIs at Zalando, KAWO, Wiredcraft, HP, and IBM, including products for brands such as Dior, Walmart, Starbucks, Adidas, and Nike. I also built a RAG application for querying Strava training data and a Node.js dictionary tool published on NPM.

Experience

Work history, roles, and key accomplishments

Senior Software Engineer

Monta

Feb 2024 - Mar 2025 (1 year 1 month)

Owned billing and invoice generation pipelines in Kotlin, processing monthly invoicing across the platform's user and operator base. Collaborated with Data Science team on data processing pipelines for reporting and analytics.

Kotlin PHP Microservices Data Processing Billing On call Support

Senior Software Engineer

Klar

Feb 2021 - Jan 2024 (2 years 11 months)

Owned core backend services across transactions, lending, and notifications in a Kotlin microservices architecture, supporting a customer base that grew past 1M users. Designed and built event-driven systems powering real-time experimentation and data collection.

Kotlin Spring Boot AWS Kafka Microservices Event Driven Architecture Mentorship On call Support

Software Engineer

Zalando

May 2020 - Oct 2020 (5 months)

Built and shipped features for Retail Center, internal tooling supporting collaboration between commercial and retail operations teams. Developed services in Kotlin and Scala within Zalando's microservices ecosystem.

Kotlin Scala Microservices

Senior Backend Engineer

KAWO

Sep 2018 - Sep 2019 (1 year)

Built backend services in Java and Node.js for a SaaS platform serving global sports and fitness brands. Designed and shipped APIs powering mobile and web client experiences.

Java NodeJS Play Framework API Design

Senior Backend Engineer

Wiredcraft

Dec 2017 - Sep 2018 (9 months)

Built WeChat Mini Program backends for global brands including Dior, Walmart, and Starbucks. Designed client-facing APIs in Node.js, working directly with brand stakeholders.

NodeJS API Design WeChat Mini Program