Senior software engineer in Dhaka. I build AI agents, MCP tool servers and guardrails for banking and mobile-wallet products.https://xack20.github.io/https://xack20.github.io/work/agentic-cms-assistant/https://xack20.github.io/work/agentic-cms-assistant/Bank operators ask about products, cards and transactions in English or Bangla. The assistant finds the right screen or prepares the change, and nothing takes effect until a person approves it.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/mcp-tool-servers/https://xack20.github.io/work/mcp-tool-servers/KONA's agents reach the card system only through MCP tool servers, and I designed and wrote most of them: 31 tools in three tiers, an action catalog for less common jobs, and a screen finder over 156 portal screens. The same servers are used for Nagad.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/agent-evals-guardrails/https://xack20.github.io/work/agent-evals-guardrails/Input screening, PII redaction, limits on tool calls, and a check for numbers the model states without looking them up. I also wrote the eval suite that tests them: 57 suites and 2,265 cases.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/kon-ai-nagad/https://xack20.github.io/work/kon-ai-nagad/The same agent stack inside the Nagad mobile wallet, for customers and guests. It answers in Bangla, English or Banglish and points people to the right screen. The PIN-safety rules are written in code.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/self-hosted-llms-rag/https://xack20.github.io/work/self-hosted-llms-rag/I set up KONA's LLM stack on an NVIDIA DGX Spark, put the models behind one gateway and moved our agents onto it. I also built a RAG over 54 card specifications that our card personalization engineers use every day.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/tag-explorer/https://xack20.github.io/work/tag-explorer/Fund tracing for a KRW-pegged card system. Each transaction becomes a UTXO with a lineage tag, so auditors and regulators can follow a balance back to its source.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/card-reporting-data/https://xack20.github.io/work/card-reporting-data/A dashboard API for card issuers, cardholder reports scoped to each bank, an ETL that records what each load did, and Superset dashboards built from code, on KONA's Oracle star-schema warehouse.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/ncp-fabric/https://xack20.github.io/work/ncp-fabric/A token-backed commerce platform for KONA I. I worked on offline transaction signing, HSM-backed identities and messaging that recovers after a broker outage, and was its top contributor.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/nid-kyc/https://xack20.github.io/work/nid-kyc/Reads KYC fields from Bangladeshi NID cards in Bangla and English. Cloud Vision reads the text, a small Gemini model parses it, and a larger one re-reads only the fields the rule checks flag, from crops of the photo.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/hisaab/https://xack20.github.io/work/hisaab/Reads bKash, Nagad and bank SMS, encrypts the data end to end, and runs its AI on the phone.Fri, 09 Oct 2026 00:00:00 GMThttps://xack20.github.io/work/whichllm-scraper-fix/https://xack20.github.io/work/whichllm-scraper-fix/whichllm ranks local LLMs partly by a benchmark it scrapes. The site changed format, every fetch failed without an error, and rankings ran on an old snapshot. I parsed the new format and made sure a live fetch can only add models.Fri, 09 Oct 2026 00:00:00 GMT