Introduction

COSCUP 2026 was held on August 8–9 at National Taiwan University of Science and Technology (NTUST) in Taipei. As one of Taiwan’s largest annual open-source gatherings, COSCUP brings together developers, users, communities, and open-source advocates from Taiwan and around the world.

This year was particularly international. COSCUP was co-hosted alongside UbuCon Asia 2026 that feature more than 20 tracks and dozens of community booths. Among them, the PostgreSQL community had a much stronger international presence this year.

I was honored to represent the international PostgreSQL community at COSCUP this year, together with Bruce Momjian, Robert Treat, and Grant Zhou from HighGo, joined by Julien Rouhaud and Mr. Ku from the local community. Together, we brought PostgreSQL to Taipei through a series of talks and a dedicated PostgreSQL community booth, where we had the opportunity to meet and connect with Taiwan’s open-source community face-to-face.

It was also the first time visiting Taiwan for Bruce, Robert, and Grant. I was glad to see them enjoy the people, food, and atmosphere of Taiwan. As a bonus, we also got to experience a little bit of Taiwan’s summer tradition, a typhoon.

Overall, it was a great conference to be part of, filled with meaningful conversations, new connections, and plenty of PostgreSQL. In this post, I’d like to look back at COSCUP 2026 from my own perspective and share some of the highlights from our time in Taipei.

<WARNING> Long post ahead

The Welcome Party

The COSCUP experience actually started the evening before the conference with the Welcome Party at Hua Shan Ding Bistro in Taipei. It was a casual gathering that brought together people from many different open-source communities and tracks—including Ubuntu, Python, and many others—to have a drink, meet new people, and talk about all things open source before the busy conference weekend began.

There were not many PostgreSQL folks at the party, but we still had a great time and met several interesting people from other communities. One detail I particularly liked was the collection of personality stickers attendees could put on their shirts—things like “Use Claude Code,” “Prefer Mandarin,” or “English Only.” It was a simple and fun way to tell others a little about yourself without even starting a conversation, and helped break the ice between people from different countries and communities.

And, of course, with drinks and beer being served throughout the evening, it was a great way to relax, make some new friends, and get COSCUP started.

Keynote: The Invisible Architecture — From Kernel Patches to Global AI – Rex Tsai 蔡志展

One of the keynote sessions was “The Invisible Architecture: From Kernel Patches to Global AI” by Rex Tsai, Engineering Director at Canonical and a long-time contributor to Taiwan’s Ubuntu and open-source communities. Rex took us through Ubuntu’s evolution from the “friendly Linux” desktop of 2004 to an increasingly invisible layer of infrastructure powering cloud, enterprise, edge computing, and today’s rapidly growing AI ecosystem.

A particularly interesting topic was what Rex called the “AI Tax”—the engineering time lost dealing with CUDA mismatches, kernel and driver incompatibilities, broken dependencies, and other environment issues instead of actually developing AI applications. He showed how Canonical is working to reduce this friction through closer hardware enablement, reproducible development environments, and technologies such as Snaps for AI deployment.

Rex closed by bringing the discussion back to Taiwan. With Taiwan at the center of the global semiconductor and hardware ecosystem, he highlighted the opportunity for the local open-source community to contribute not only to hardware manufacturing, but also to the open software infrastructure that powers the next generation of AI.

Keynote: From Taiwan-LLM to the Frontier — What Open Source Taught Me, and Why I Still Miss It – Yen-Ting Lin 林彥廷

Another keynote I enjoyed was “From Taiwan-LLM to the Frontier: What Open Source Taught Me, and Why I Still Miss It” by Yen-Ting Lin, Research Scientist at Google DeepMind and creator of the Taiwan-LLM project. He shared his journey from building open-source language models for Taiwan to working on post-training and frontier model research.

Taiwan-LLM started at a time when models such as ChatGPT often struggled with Traditional Chinese and Taiwan-specific language and knowledge. Rather than competing purely on general intelligence, the project found its own niche: Taiwan localization. The team collected local data, incorporated expert knowledge, trained for Taiwan-specific language use, and released models and demos openly so that real users could provide feedback. Lin also walked through how this evolved from language fluency in the first version, to common tasks, and eventually toward reasoning capabilities.

One takeaway I found particularly interesting was his perspective on the role of open-model developers in the AGI era. As frontier models become increasingly powerful and expensive to compete with directly, open-source developers need to find where they can provide unique value, while becoming much better at evaluating what models can and cannot do. Despite now working at the frontier of closed-model research, his message was clear: contributing to open source remains a valuable investment—and an experience he still misses.

The PostgreSQL Community Booth

This year, thanks to an initiative led by Mark Wong and the PostgreSQL community, we were able to bring a dedicated PostgreSQL community booth to COSCUP. Bruce Momjian, Robert Treat, Grant Zhou, and I traveled to Taipei as part of the international PostgreSQL community presence, joining local community members to promote PostgreSQL and PostgreSQL.TW.

Before setting up the booth, we also took the opportunity to give PostgreSQL a little extra visibility around Taipei—with a group photo holding the PostgreSQL banner at Liberty Square, in front of Chiang Kai-shek Memorial Hall. It turned out to be one of my favorite photos from the trip and a fitting way to start our “PostgreSQL in Taipei” weekend.

At the booth, we had plenty of PostgreSQL swag to give away, including T-shirts, hoodies, stickers, notebooks, and other goodies. But more importantly, we met many local PostgreSQL users—and it was great to see how much enthusiasm there is for PostgreSQL in Taiwan. We talked about ways to participate and contribute to the global PostgreSQL community, as well as initiatives from PostgreSQL.US (PgUS) to help people around the world establish and grow local PostgreSQL user groups, including providing resources and financial support.

With everyone also attending or delivering talks, we had to take turns keeping the booth staffed throughout the conference. At one point, while the rest of us were attending sessions and buying lunch, Bruce Momjian was left holding down the PostgreSQL booth by himself. How often do you walk up to a community booth at a conference and find Bruce there waiting to talk PostgreSQL with you? 😄 It was a unique experience for us—and probably for quite a few attendees as well.

Overall, the booth gave us exactly what we had hoped for: a place for the international and Taiwan PostgreSQL communities to meet face-to-face, exchange ideas, and hopefully encourage more people in Taiwan to become involved in the wider PostgreSQL community.

The PostgreSQL Taiwan Track

Beyond the booth, PostgreSQL also had its own dedicated track at COSCUP this year. Bruce Momjian, Robert Treat, Grant Zhou, Julien Rouhaud, and I each delivered a session along with several other local and international speakers, giving local PostgreSQL users a mix of technical topics, practical PostgreSQL tips and insights, and discussions about community building. Most of our talks happen on day 2 of the conference.

Making Postgres Central in Your Data Center — Bruce Momjian

Bruce Momjian, PostgreSQL co-founder and core team member, presented “Making Postgres Central in Your Data Center,” exploring why PostgreSQL is uniquely positioned to become a central database within an enterprise data architecture.

Bruce started with one of PostgreSQL’s fundamental strengths: its object-relational design and extensibility. PostgreSQL exposes much of its functionality through objects and system catalogs—from data types and operators to functions, aggregates, languages, and extensions—allowing the database to be extended far beyond a traditional relational system.

Combined with foreign data access and its ability to support relational, NoSQL-style, and data warehousing workloads, this extensibility allows PostgreSQL to connect and aggregate data from otherwise separate systems. The talk was a great reminder that PostgreSQL’s strength is not only in storing data, but in its ability to sit at the center of an increasingly diverse data ecosystem.

Index Best Practice and Hypothetical Indexes in PostgreSQL — Julien Rouhaud

Julien Rouhaud presented “Index Best Practice and Hypothetical Indexes in PostgreSQL,” a practical look at PostgreSQL’s powerful and highly extensible indexing capabilities.

The talk walked through the different index access methods and their use cases, including B-tree, Hash, GiST, GIN and BRIN, while explaining how data types, operators and operator classes determine which indexes can actually be used. Julien also covered useful features such as partial indexes, covering indexes and index-only scans, showing how choosing a more specialized index can reduce its size and improve performance.

An important takeaway was that indexes don’t solve everything—a poorly designed query or schema cannot necessarily be fixed simply by adding another index. Julien therefore also introduced HypoPG, which lets users create hypothetical indexes and see how PostgreSQL’s planner would use them without paying the cost of actually building the indexes. This provides a very practical way to evaluate indexing strategies before making changes to a production database.

I Didn’t Know Postgres Could Do That! — Robert Treat

Robert Treat presented “I Didn’t Know Postgres Could Do That!”, a developer-focused tour of PostgreSQL features that are powerful but sometimes overlooked. Rather than viewing PostgreSQL simply as a database managed by DBAs, Robert showed how many of its capabilities can directly simplify application development.

Through a series of practical examples and “tricks,” he covered features such as ICU case-insensitive collations, useful SQL patterns including INSERT ... RETURNING, and ways to experiment with indexes inside a transaction using CREATE INDEX and EXPLAIN ANALYZE followed by ROLLBACK. Along with PostgreSQL’s rich data types, indexing and query capabilities, the session demonstrated why developers can often push more application logic and functionality into PostgreSQL instead of rebuilding it in the application layer.

It was a fun reminder that even experienced PostgreSQL users can still occasionally find themselves saying, “I didn’t know Postgres could do that!”

Building a PostgreSQL Open Source Community in China: From Local Users to Global Collaboration — Grant Zhou

Grant Zhou shared his experience building and growing the PostgreSQL community in China, with a particular focus on turning a large regional user base into stronger participation in the global PostgreSQL ecosystem.

The talk covered community events, education and the PostgreSQL China training and certification program, as well as downstream open-source projects such as IvorySQL and SynchDB, which address real-world enterprise migration and heterogeneous data synchronization needs. Grant also discussed some of the barriers Chinese developers face when contributing upstream, including language, mailing-list culture, and the PostgreSQL review process, and introduced approaches such as a “buddy system” where experienced contributors help newcomers review patches and prepare communications before engaging upstream.

The session concluded with a broader message of local scale, global impact: regional production experience can provide valuable feedback to PostgreSQL upstream, while closer collaboration among communities in China, Taiwan, the wider Asia-Pacific region, and the global PostgreSQL project can create more opportunities for technical exchanges, documentation, education, and contributions.

As one of Grant’s final slides nicely summarized: “Code runs databases; people build communities.”

My Journey from First Patch to PostgreSQL Significant Contributor — Cary Huang

In this personal talk, I shared my seven-year journey contributing to the global PostgreSQL community and some of the lessons I learned along the way.

I shared my seven-year journey contributing to the global PostgreSQL community, which started not with patches, but with writing technical blogs while learning PostgreSQL internals. At my first PostgreSQL conference, people I had never met recognized me through those articles and told me they had helped them learn PostgreSQL. That experience inspired me to contribute more.

The talk emphasized that PostgreSQL contribution takes many forms—blogs, documentation, patch reviews, talks, volunteering, user groups, and code. Code contributions can be the hardest path, and many of my early patches were rejected or went nowhere. For newcomers, I recommend starting with patch reviews, learning how the community works, and finding contribution opportunities along the way.

After years of reviews, writing, community involvement, and development, my Parallel TID Range Scan patch was committed for PostgreSQL 19, contributing to my recognition as a PostgreSQL Significant Contributor. My message to Taiwanese PostgreSQL users was simple: start small, participate consistently, and your contributions will add up over time.

Beyond the Talks: Professional Photos, Lightning Talks & Hacking Corners

COSCUP offers plenty to experience beyond the scheduled conference sessions. Attendees can visit the professional photo area, where onsite photographers capture the conference throughout the weekend and a dedicated room offers free professional portraits and group photos—a nice touch for community groups visiting from around the world.

The Lightning Talks are another fun COSCUP tradition, giving attendees a few minutes on stage to quickly share a project, idea, community activity, or anything interesting. Rather than requiring a full conference proposal months in advance, topics can be submitted during the conference and selected shortly before the session.

The format reminded me of PGConf.dev, where attendees can also submit lightning-talk ideas during the conference, with a small number selected for presentation the following day. It creates a much more spontaneous atmosphere and gives people who are not part of the regular program an opportunity to share something with the community.

For something even more informal, the Hacking Corners provide open spaces where anyone can sit down with others to code, brainstorm, work on documentation, discuss an open-source project, or simply continue a conversation from an earlier talk. There is no formal agenda or reservation required—just find a space, gather some people, and start hacking.

Explore Taipei City with PostgreSQL Folks

After two busy days at COSCUP, we finally had some time to slow down and explore Taipei together. Conferences are not only about talks, booths, and technical discussions—some of the best community connections happen outside the conference venue.

We walked around the city, enjoyed local food, visited some of Taipei’s landmarks, and, naturally, continued talking about PostgreSQL along the way. It was a great opportunity to spend time together beyond the conference and introduce our visiting PostgreSQL friends to a little more of Taiwan.

For Bruce, Robert, and Grant, this was their first visit to Taiwan, which made the experience even more special. PostgreSQL brought us together, but the friendships and experiences around it are what make the community memorable.

Interesting Background Story – How We Ended Up in Taipei

Interestingly, earlier this year, none of us knew much about COSCUP or PostgreSQL.TW. We first heard about them from Chris Travis at HOW 2026 in Jinan, who mentioned that Taiwan had this great open source conference called COSCUP and that there is a Postgresql user group there as well, but with not much global presence. Having been born and raised in Taiwan, that immediately caught my attention. Soon after, Mark Wong suggested that I attend COSCUP and organize a PostgreSQL booth.

The plan really came together at PGConf.dev 2026 in Vancouver, when Bruce, Grant, Mark, and I met again over BBQ. COSCUP came up, and we decided that night to participate—coincidentally, it was also the CFP deadline, so we submitted our talks to the PostgreSQL Taiwan track right there.

My talk was accepted quickly, while several others remained pending. The organizers had received multiple international submissions at once and were understandably cautious, while also facing limited room in the schedule. After some discussion, they went the extra mile to arrange an additional room for our talks, which we greatly appreciated.

What started with a conversation in Jinan and another over BBQ in Vancouver eventually brought us all to Taipei. With international PostgreSQL contributors joining the local community in person, we hoped to bring more global visibility to PostgreSQL.TW and build a stronger connection between Taiwan and the wider PostgreSQL community.

Coming Next: PGConf.Asia 2026 in Hong Kong

The connections we made at COSCUP will continue later this year at PGConf.Asia 2026, taking place November 17–18 in Hong Kong.

PostgreSQL turns 30 this year, and PGConf.Asia returns to Hong Kong for a renewed chapter. Since its first edition in Japan in 2016, PGConf.Asia has brought together PostgreSQL users, developers, contributors, companies, and local communities from across Asia for technical exchange and regional collaboration.

If you enjoyed meeting the PostgreSQL community at COSCUP—or want to become more connected with PostgreSQL communities across Asia—come join us in Hong Kong this November!

Final Thoughts

Overall, COSCUP 2026 was a fantastic open-source conference and community experience. What impressed me most was not only the scale and diversity of the talks and communities, but also the people behind the event.

More than 100 conference staff and volunteers worked behind the scenes on everything from organization and venue operations to technical support, photography, video recording, and countless other details. Much of what attendees experience over those two days is made possible by people generously contributing their own time and effort. That volunteer spirit is, in many ways, exactly what open source is about.

For us, COSCUP was also an opportunity to connect the global PostgreSQL community with PostgreSQL users and contributors in Taiwan, make new friends across other open-source communities, and experience a very different kind of community conference.

I would definitely come back again. See you at the next COSCUP!