Backend developer, Dcard, Jun. 2017 – Feb. 2021
The biggest social media app in Taiwan. (
App store)
This position works closely with the infrastructure team members, data scientists, and product managers. Dcard is the most popular social media app in Taiwan.
- Support data-team built data pipeline and data center for our home page recommendation system.
- Implemented dictionary compression utility for a high writing-load database with a 95% compression rate and 60% insert speed improvement.
- Improved Elasticsearch performance and conducted new query implementation. Rewrote index mapping; as a result, the new index was reduced by 40%, allowing us to build an auto-reindex trigger.
- Created the Node.js service template and CloudFlare worker’s template. Provided a quick and easy environment for developers.
- Added or removed indices and materialised view for our PostgreSQL. Improved query performance. Reduced API response time to 400ms.
- Analyse and optimise multi-layer cache, including service internal local cache, Redis cache, CDN, and CDN internal worker.
- Constructed a dynamic server-side rule-based configuration service that now handles at least 100 different rules.
- Developed a subscription feed service that handles thousands of new posts every hour and feeds to millions of subscribers.
- Cooperated directly and efficiently with the sales department. Responsible for the scheduled ticketing system, check-in system, real-time participant calculations, and activity website. Developed a highly successful offline activity with the sales team, attracting over 10,000 participants.
- Established a ticketing and gift delivery service, which handled 15,000 draw requests per minute at the peak time. More than ten thousands gift delivery campaigns were processed.
- Responsible for advertisement system, e-commerce service (including the checkout process, in-stock management, and all web pages), and advertising post scheduling system.