2025 in Review

Reflecting on the year 2025.

Starting a new job#

Early this year, I started working at a new fintech startup company in a similar role as my previous role at Seek: Senior Engineer. The first team when I joined the company was building & selling a dedicated solution for our clients. In the beginning, I found myself disappointed a couple of times because a lot of things: the infrastructure, processes are not there. But I gave it a chance to stay and see “what happens” after a couple more months. This is the youngest company (around 4 years old in operation) I joined in career so I wanted to learn how things are being done at this stage. Now almost a year, I’m still here.

In my previous company, I personally felt like it was really hard to make an impact as an engineer. My schedule was filled with meetings which I have gotten used to it by now. Selling an idea to the team with just influence, took so many days and very tiring since there were many stakeholders to convince before I could start writing code. Part of the reason I joined a startup is that so I can make an impact much more quickly without all those bureaucracy. Now, the only people I have to convince & get concensus are two people sitting next to me in the office and the CTO who sits two aisles away in the same room.

The first few months I joined the team, I was reviewing a lot of PRs. In my opinion, this helps establish a impression on me, help me build the relationship with the team and also it help me understand which component of the system in need to focus on. In the early days, it’s important for you to learn each others’ style and the team preferences.

In this team, I learned a lot about fintech industry and security as a whole. This is when I learn and get new hands-on experience working with mTLS, certificate chains, encryption, etc. While here, as an Individual Contributor, aside from day-to-day feature and integration implementations, I also contributed to performance improvement by fixing the broken keep-alive connection in the system and improving the system’s reliability by fixing the graceful shutdown mechanism. I am one of the few engineers on the team who writes Go, so I am one of the people who regularly reviews PRs written in Go.

Promoted to Tech Lead#

As the company’s engineering team grew significantly, we needed to split the team in two so that each could focus on their respective problem effectively. There are now two teams in the organization, one for each product we are selling. In August 2025, I was promoted to lead the sibling team, which sells a SaaS & public API solution. Since this was the company’s first product, the engineers on the team had deep domain knowledge, and the system and infrastructure setup were already well-established.

It feels great to be able to help the team with my experience in the past. It fits me perfectly since the team are focusing on working with cloud, APIs, backend, etc. and not much on the AI and frontend/mobile app development.

Part of my role is to still be actively involved in hands-on coding while doing some high-level work & people management. You can read more about my role as a Tech Lead in my previous blog post.

When I first took over the team, there were only 3 direct reports, and including Product Manager, only 5 members in the team. However, as the business grew and so does the team, there are now 8 people in the team doing cross-functional works: backend development, QA and DevOps. Honestly, as an introvert person, playing this role is not easy & overwhelming. In mid-2025, I was really busy interviewing 10s of candidates for junior software engineer role in the team. I’m glad that we got a really good engineer joining the team.

While here, I was:

Fixing problems in many areas, including API gateway deployment and Kafka configuration.
Bridging the team and encouraging communication.
Writing new guides, processes & internal tooling to help engineers deliver project faster & deploy confidently
Mentoring engineers to help them grow.

As a line manager, for the first time I sat in many performance review discussions this year. It was a really eye-opening experience.

Launched my first mobile app with a friend#

An ex-colleague from my previous company reached out to me with an idea to build an app. It’s always been my dream to have my own app published on the Apple App Store and Google Play Store. He has the expertise working on the frontend & mobile app so that compliments me.

So I’ve been building the app’s API server using Go and a modular monolith architecture. The system has only one dependency: a PostgreSQL database. It’s so refreshing to build an intentionally simple system that is also extensible while maintaining high performance and being cheap/easy to operate.

After many months of building, the app is finally launched on the Apple App Store, but it’s not at a stage where I’m proud to share it with everyone yet.

The mobile app itself is built using React Native & Expo by my partner. I really wish I could learn to build mobile app on my own either using React Native or Swift so that I can ship an app on my own. But honestly, until now, I’m still not motivated enough to actually start learning mobile app development.

Contributing to open source projects#

Aside from my day-to-day work, I found myself contributing more to the open-source community in 2025. I have created a patch for Gatus, the goakt/ego framework, and made many other small contributions. Some of them are from patch I did at work and submiting to upstream, most of them are from my own interest. I wish to get involved more in the community in 2026.

Technologies I’m excited about#

Message brokers: Tansu, Kafscale, Warpstream, Liftbridge, S2.dev
S3-backed databases: Turbopuffer, Arc, Litestream, SlateDB
AI-assisted coding: Claude Code & Cursor
Tanstack Start for frontend work

What’s next#

Career-wise, I’m learning a lot in my current role from everyone in the team, both juniors and seniors. I feel valued because I can contribute to solving team problems and help individual members grow. That’s the most satisfying feeling for me. I would love to guide the team to be a more matured team, and have a better standard even without me. That’s my end goal.

Working in startup has a lot of rough edges. Many of the process, toolings and knowledge are not matured. There are holes everywhere. Alternately, I could just leave the company to go and work somewhere more organized and matured. However, this time I choose to embrace the chaos and improve the team & system instead. It’s a learning experience for me too.

Read the similar topic but for previous years: 2024, 2023, 2022, 2021