Jirapath.

Backend Software Engineer · Banking platforms

Building reliable backend systems for banking and enterprise platforms.

I'm Jirapath (Sun) Charoenpanyapratch. I have 4+ years of experience building Java Spring Boot microservices, REST APIs, batch processing and CI/CD pipelines. I currently deliver Mobile Banking features at TMBThanachart Bank.

View work Download CV

Nonthaburi, Thailand · GitHub ↗ · LinkedIn ↗

● Selected impact

What changed because of my work

70%

Faster API responses on large-payload requests

I optimized these endpoints on the TMBThanachart Mobile Banking backend.

40

Microservices migrated, Spring Boot 3 → 4

I led the migration and kept framework and dependency compatibility with minimal production risk.

10+

Banking service teams integrated

At Krungthai Bank, I designed and integrated APIs with these teams for cross-department data exchange.

1M+

Users on the platform I build for

I deliver and maintain customer-facing features on this Mobile Banking platform. The figure is the platform's scale, not my own.

● Selected work

Case studies

Three pieces of production work from my current role.

Graph-RAG knowledge base for AI agents

TMBThanachart Bank · Customer onboarding

Problem
Incident diagnosis, onboarding and impact analysis across 30+ microservices relied on scattered specifications, and AI assistants would answer without evidence.
My contribution
I structured 1,000+ Markdown specifications (services, 100+ database tables, activity logs) into a Graph-RAG knowledge base. I wrote a Python generator for a two-level service and endpoint dependency graph. I also wrote the agent instruction framework (guardrails, task routing and a confidence model), so GitHub Copilot and Claude answer only from traceable evidence. On top of that I built reusable skills: flow tracing, impact analysis, comparing logs against the specs, API contract linting, Liquibase changeset generation and automated merge-request review against the specs.
Outcome
Incident diagnosis, onboarding, impact analysis and migration scripting are faster, and agent answers are grounded in cited specifications rather than guesses.

PythonGraph-RAGPrompt engineeringPlantUMLLiquibaseGitLab API

Release automation for 30+ microservices

TMBThanachart Bank · Backend / DevOps

Problem
Releases and cut-offs across 30+ Spring Boot services on GitLab, Jenkins and AKS involved repetitive manual steps, and slow pipelines held up delivery.
My contribution
I built a Python toolkit that bulk-updates repositories and merge requests, triggers Jenkins image builds and AKS deployments in bulk and verifies each one, and generates daily cut-off reports for 3 squads. I built a pipeline benchmark that times tests, SonarQube analysis and Docker builds, and used it to find speed-ups such as the Gradle configuration cache. I cut Docker build-context size with .dockerignore. I also built a Docker Compose local environment (PostgreSQL, MongoDB, Redis, Kafka) with mock downstream APIs for end-to-end testing.
Outcome
There is less manual release and cut-off work, and build, deploy and code-update steps are consistent across 30+ services.

PythonJenkins APIGitLabDockerAKSGradleSonarQube

Spring Boot 3 → 4 migration

TMBThanachart Bank · Mobile Banking backend

Problem
40 production microservices behind a Mobile Banking platform had to move to a new major framework version. Each one needed compatible framework and dependency versions, without risking production.
My contribution
I led the migration across all 40 services and handled framework and dependency compatibility.
Outcome
All 40 microservices run on Spring Boot 4, and the migration kept production risk and downtime to a minimum.

JavaSpring BootMicroservices

● Open source

Libraries and open data

Public projects I build and maintain.

  • promptparse-jvm ↗

    Maven Central · Apache-2.0

    A zero-dependency library for generating, parsing and validating Thai PromptPay and EMVCo QR payloads, including TrueMoney, BOT barcodes and slip pre-checks. Java-friendly, immutable and thread-safe.

    KotlinJavaEMVCo QRGradle

  • slipverify-jvm ↗

    Maven Central · Apache-2.0

    Verifies Thai bank-transfer slips: finds the QR in a slip image, parses it with promptparse-jvm, confirms it with EasySlip or SlipOK, checks amount, receiver, age and duplicates, and returns one typed result with reason codes. Includes a Spring Boot 4 starter.

    KotlinSpring BootRedisZXing

  • thai-auto-data ↗

    Open data · CC BY 4.0 · Live dashboard ↗

    Monthly new-car registrations in Thailand since January 2021, by brand, model, province and fuel type, from the Department of Land Transport, plus official prices. Published as CSV with a bilingual interactive dashboard.

    JavaScriptCSVGitHub Pages

More on GitHub ↗

● Experience

Where I've worked

  1. Nov 2024 – Present

    Senior Associate Software Engineer

    TMBThanachart Bank PCL

    • Deliver and maintain customer-facing Mobile Banking features on Java Spring Boot microservices for a platform serving 1M+ users.
    • Cut API response time by 70% on large-payload requests and streamlined the Jenkins CI/CD pipelines.
    • Led the Spring Boot 3 → 4 migration across 40 microservices with minimal production risk and downtime.
    • Built a Graph-RAG knowledge base and agent instruction framework so GitHub Copilot and Claude answer from traceable specifications. It is used for incident diagnosis, onboarding and impact analysis.
    • Built Python release automation for 30+ microservices across GitLab, Jenkins and AKS, plus a Docker Compose local environment and mock downstream APIs for end-to-end testing.

  2. Dec 2022 – Nov 2024

    Java Software Engineer

    Krungthai Bank PCL

    • Designed and implemented high-performance Java Spring Boot REST APIs for an internal financial application.
    • Built reliable Go batch processing for data import/export and user notifications.
    • Worked with 10+ banking service teams to design and integrate APIs for cross-department data exchange.

  3. May 2022 – Nov 2022

    Software Developer

    Sirisoft PCL

    • Built NoSQL applications with Java, Spring Boot and Kafka for Online Marketplace clients.
    • Designed the infrastructure for an internal Timesheet project, then built and maintained its backend with Spring Boot, Docker, CI/CD, API Gateway and AWS.

  4. Jun 2021 – Apr 2022

    Full-stack Developer (Intern)

    Krungthai Panich Insurance PCL

    • Designed and built a customer notification system on GCP, designed its APIs from the business logic and wrote the documentation.
    • Cleaned and analyzed business data with Python, and automated web service and load testing with Selenium and JMeter.

  5. 2018 – 2022

    B.Eng. Computer Engineering

    King Mongkut's University of Technology North Bangkok

● Expertise

What I work with

Backend

  • Java, Kotlin, Spring Boot
  • REST API design
  • Microservices
  • Go batch processing
  • Kafka
  • Feign, MapStruct, JUnit, Mockito
  • Performance tuning, caching

Data

  • PostgreSQL, SQL Server
  • MongoDB
  • Redis
  • Elasticsearch
  • Liquibase migrations
  • Python for data and automation
  • Graph-RAG, LLM agent tooling

Platform

  • Docker, Docker Compose, Kubernetes
  • Azure (AKS, Blob Storage)
  • Jenkins, GitLab, SonarQube
  • AWS (API Gateway, S3, Lambda)
  • GCP
  • Git, migration planning

● Contact

Get in touch

I'm open to senior backend roles and interesting engineering problems. Email is the fastest way to reach me.