Ari Stifandi
Senior software engineer · backend & LLM systems
8 years building backend systems and LLM-powered products across AI SaaS, fintech and capital markets. I ship agentic features end to end, then own what keeps them alive: reliability, observability and infra cost.
Jakarta, ID · GMT+7 · Go / TypeScript / Python
- ARR in an AI launch's first month
- $600K
- infra cost on a market data platform
- −80%
- cheaper agent queries via one MCP server
- 6×
- exchange events processed in under 5 min
- 2M+
// selected work
06 entries- 01· AI SaaS$600K ARR
AI email assistant
Core engineer on the launch. Hit $600K ARR in month one, then cut email labeling cost 8.6×.
- 02· AI SaaS6× cheaper
Agentic copilot & MCP tooling
Rebuilt an in-meeting copilot on MCP tools with voice I/O, cost telemetry and provider fallback. Merged a chat assistant's tools into one MCP server.
- 03· AI SaaS−90% alerts
Meeting-bot reliability
Own recording bots across 8 video platforms. Moved capture from DOM scraping to WebRTC and CDP signals. Alerts 100k → 10k a day, support tickets −70%.
- 04· Fintech2× retention
LLM assistant & document OCR
Built a provider-agnostic LLM layer over OpenAI and Anthropic. Shipped receipt and bank-statement scanning that doubled first-month retention.
- 05· Fintech−50% NPL
Credit scoring rebuild
Rebuilt ML credit scoring: cost and NPL both down about 50%. Live model A/B tests went from 2 months to under 2 weeks.
- 06· Capital markets−80% infra
Real-time market data
Direct exchange feed integration that replaced third-party vendors. 2M+ events in under 5 minutes, peak VMs 50 → 8.
// stack
what I reach for- languages
- Go, TypeScript, JavaScript, Python, Java, Ruby, C#
- backend & data
- Node.js, NestJS, Spring Boot, Django, GraphQL, PostgreSQL, MongoDB, Redis, Kafka
- ai / llm
- Agentic systems, MCP servers, LLM evals, RAG, OpenAI, Claude, Gemini
- cloud & web
- GCP, AWS, Azure, Alibaba Cloud, Sentry, Grafana Loki, React, Next.js
// side projects
github.com/ad17-2- agentTool-calling agent library on the Vercel AI SDK: multi-turn history, retries, per-run cost, a context budget and MCP tools.TypeScript · AI SDK · MCP
- stacktailRead-only MCP server that lets Claude Code query Loki logs and Sentry issues, so an agent can debug prod on its own.Go · MCP · Loki · Sentry
- macro-mapOne-page macro dashboard for an investor in Indonesia. Every number says what it means, not just where it is.Python · live at macro.aristifandi.io
- logbookTrip planner for truck drivers: hours-of-service rest stops and daily duty-status log sheets.React · TypeScript · Django · Leaflet · live at logbook.aristifandi.io
- requirement-makerCLI that turns meeting recordings into requirement docs, with parallel Whisper + Claude passes.Python · Whisper · Claude
// contact
Jakarta · GMT+7Happy to talk shop about backend systems, agents and cutting infra bills. Email is fastest; a 30-minute call works too.