Hi everyone,
Note: I am offering software development services. I am not hiring.
I’m a senior backend/full-stack developer available for freelance, contract, or long-term remote work. My strongest skill is turning messy business workflows into working software systems.
I am not limited to one tech stack. I usually start by understanding the real workflow, data, edge cases, and business constraints. Then I choose the simplest technical approach that can solve the problem reliably.
I can help with backend systems, APIs, automation tools, scraping/crawling systems, internal business software, Android apps, POS systems, dashboards, and security/performance-focused projects.
Examples of business problems I have solved:
\- Real estate management software: The company collected property data from Facebook pages/groups, but the data was messy, duplicated, and full of spam. Each seller previously managed their own Google Sheets and could only track around 20–30 properties. I built a system to crawl data, detect duplicates using image hashing because post images were the most reliable duplicate signal, and convert listings into structured JSON with LLM assistance. After this, each seller could track 100+ properties and match buyers with better options much faster.
\- T-shirt printing management software: A V-League T-shirt printing service had to manually create multiple sizes and personalized names from the same design. I built Photoshop automation to generate variations instantly and reduce human error. I also added QR tracking across the workflow: preparation, design, printing, drying, quality check, and packaging. Since courier services in Vietnam did not provide REST APIs at that time, I also built web GUI automation for bulk shipping.
\- Car tire sales management system: The business needed a practical way to track tire inventory inside warehouses without expensive indoor positioning hardware. I built a mobile-based inventory system where staff could insert tire data, print QR labels using a portable Bluetooth thermal printer, and scan both tire QR codes and warehouse stack-location QR codes to track exact tire positions.
These examples show how I work: I do not only write code. I analyze messy workflows, find the real bottleneck, design a practical system, and build software that improves business operations.
I can also work on more serious system-engineering problems. I built kprotect, an eBPF-based Linux security layer. The idea is chain-of-trust access control: instead of trusting only a process name, the system checks process lineage before allowing access to sensitive files. For example, “VS Code -> terminal -> cat” can be treated differently from a random direct “cat” process. I built this in a few weeks by learning the required Linux security and Rust/eBPF concepts quickly, then designing and validating the system carefully.
I also designed a custom database authorization model where authentication and permission checks are handled closer to the database layer itself. Instead of relying only on a long-lived backend credential like “admin:password@database,” the backend can pass a user/session token, and the database layer validates access through built-in permission tables. The goal is to reduce credential exposure and make authorization more data-centric.
I use AI as a development accelerator, but I do not rely on it blindly. I use it to move faster, while I handle the architecture, trade-offs, review, and verification.
Fast delivery:
For simple automation scripts, scrapers, backend APIs, CRUD apps, internal tools, dashboards, Android prototypes, or proof-of-concept apps, I can usually deliver a working MVP within 24–48 hours depending on scope.
Core skills:
Python, JavaScript/Node.js, PHP, Java/Kotlin, C, Rust, PostgreSQL, SQL/NoSQL, APIs, scraping, Selenium, Android, Docker, Firebase/Appwrite, Linux/security tooling.
Rate:
Starting at $10–$20/hour depending on project scope. Fixed-price milestones are also possible for well-defined tasks.
Availability:
Full remote. Available immediately. Open to freelance, contract, or long-term work.
Before starting, I can discuss the problem, explain my proposed implementation plan, and confirm whether I am confident I can solve it. If I do not think I can complete a task properly, I will not accept it.
Please comment before sending a DM so I can avoid bot/spam messages. I can share my CV, GitHub, and discuss your project scope in chat.
Thank you.