From Queries To Intelligence: How Ter Seesillapachai Is Rebuilding Fintech From The Inside

Reliable backend infrastructure is essential for an industry like finance, where it’s responsible for processing large transactions, tracking real-time spending, and accurately compiling data for audits and financial reporting.

And as more and more companies adopt advanced tools like AI to automate workflows and analyze large datasets with greater speed and precision, the demand for engineers who can build fast, scalable systems has also continued to grow.

At the forefront of this shift is Nithiwat Seesillapachai, better known as Ter.

He started out as a finance student before transitioning into programming, and has spent the past two years as a software engineer at an all-in-one fintech company that helps businesses manage spending and automate financial operations. Ter has played a key role in upgrading the company’s infrastructure, including building high-speed data pipelines and leading projects to reduce latency, which have raised the bar for their engineering standards.

Read on to learn more about Ter’s current role and how his work is helping push fintech forward through the development of smarter, faster systems.

Ter: A Late Bloomer In Engineering

Ter first became interested in programming while completing a bachelor’s in economics with a focus on finance at an Ivy League university. During his second year, he took an intro programming language class that led him to shift directions and pursue a second degree in computer science, with a focus on AI and machine learning.

Ter didn’t have the same coding experience as his peers, but instead of looking at this as a drawback, he treated it as motivation. The steep learning curve pushed him to dig deep into the technical fundamentals, build consistent studying habits, and catch up with his more experienced peers.

By the time he graduated, he had developed a strong foundation in economics, computer science, and, just as importantly, a way of working that emphasized learning quickly and applying his newfound knowledge in practical ways.

After a few internships during his studies, Ter started his engineering career at a startup focused on automating customer support and reducing operational costs. As a founding engineer, Ter took on multiple roles, from building the company’s backend systems to working closely with early customers. His hard work in the latter was essential for securing major clients.

This early experience not only gave him a strong foundation in building infrastructure from the ground up but also showed him how technical decisions directly affect a company’s ability to scale, both of which continue to guide his work.

Revamping Ramp’s Data Infrastructure

In 2023, the first startup Ter was working at was acquired by his current employer. Ter remained with the company through the acquisition, stepping into a software engineering role during a critical period when they were looking to integrate AI into its platform in response to a broader industry shift toward automation. But to support those initiatives, the company needed a stronger infrastructure that was capable of handling large volumes of data and allowing real-time access for both analytics and product development teams.

To solve this, Ter led the integration of the company’s infrastructure with a high-performance database designed to handle large analytical workloads. This database’s columnar storage format made it especially effective at scanning and aggregating massive datasets quickly and efficiently, making it a crucial upgrade as the company expanded its services and customer base.

Ter also built a real-time pipeline to connect the database with the company’s existing infrastructure, ensuring data could be transferred quickly and reliably without overwhelming ongoing operations.

With this new system in place, the company’s engineering teams gained the speed and flexibility they needed to build AI tools like approval intelligence and merchant correction workflows. Ter played a key role in this effort by developing calendar integration and automated bookkeeping features, systems which allowed users to lower operational costs, minimize human error, and improve cash flow management.

These upgrades also improved performance across the company’s core features by making tools like enterprise search, audit logs, and exports faster and more reliable, resulting in a smoother experience for customers at every scale.

Tackling Latency With The “Superspeed” Initiative

While the database integration significantly strengthened the company’s infrastructure, it didn’t solve all its performance problems. As the company took on more large enterprise customers, some began to experience slow response times because parts of the backend struggled to keep up with increased demand.

To fix this, Ter led a company-wide effort known internally as “Superspeed,” with the goal of identifying and fixing the slowest parts of the company’s infrastructure without interrupting ongoing development.

Ter led the project and brought in developers from six different engineering pods. He aligned them by setting shared performance benchmarks, writing internal guides to help them pinpoint bottlenecks and avoid common inefficiencies, and setting up fast feedback loops to keep momentum high. He even jumped in as a temporary team member when workloads spiked, helping clear backlogs and maintain progress.

The results were immediate. Latency was successfully cut in half across several of the company’s busiest systems, delivering a faster and more stable experience for enterprise users.

But the impact of this initiative went beyond simply improving performance. It helped establish a consistent performance standard across the company’s operations, giving both established engineers and new hires a clear reference point for how systems should operate.

What began as a tactical fix became a cultural shift in how this company builds and maintains its systems.

His Ongoing Impact

Ter’s work on important projects like the database integration and the Superspeed initiative earned him a senior software engineering role at his current company, where he’s now in charge of leading large-scale efforts from conception and team-building to execution and deployment. He focuses on establishing long-term strategies, particularly in shaping how AI systems are developed, launched, and maintained across the company.

Ter also dedicates significant time to mentoring junior engineers, regularly leading knowledge-sharing sessions, providing hands-on guidance, and helping others implement AI features effectively while fostering a culture of speed, trust, and collaboration across the company.

To learn more about Ter’s work, connect with him on professionally and explore how his current engineering team is streamlining fintech operations behind the scenes.

BDG Media newsroom and editorial staff were not involved in the creation of this content.