Wei C.

Most data work fails on the plumbing, not the model: ingestion that quietly drops rows, a pipeline nobody can re-run, an index that answers confidently and wrongly. That layer is what I have spent 14 years building. Senior software engineer, 2010–2024 — Alibaba (2010–2019), Microsoft (2019–2024). I contribute to the Apache Flink ecosystem (Flink–Kafka–HBase connector work), so streaming, state, back-pressure and exactly-once semantics are things I know at implementation level rather than from blog posts. WHAT I BUILD ▸ Pipelines that survive their second month. Kafka, Flink, Spark, HBase, Elasticsearch — batch and streaming ingestion, text and data processing, CDC with Debezium. Delivered on Upwork: a distributed Apache Nutch crawler with Python bindings feeding Elasticsearch, and Kafka + Debezium real-time log streaming. ▸ Backend services that carry the data. Java with Spring Boot and Spring Cloud, Python services, REST and event-driven APIs, PostgreSQL and MySQL — schema design, query and connection-pool behaviour. Clean module boundaries, automated tests, and the documentation the next person needs. ▸ Retrieval and agents on top of that data. Search quality is decided upstream, in ingestion, normalization and freshness — which is the part I already do. I use coding agents and LLM tooling in my own daily work, so I read machine output rather than trusting it, and I will tell you when a plain pipeline beats an agent. ▸ Enabling your team. I have mentored engineers 1:1 through Kafka, Cassandra, Spark and Flink; one current contract is exactly that — Apache Doris and Flink enablement, renewed long enough that the rate escalates automatically every three months. Handover is a habit, not an afterthought. WHAT I WON'T PRETEND English is conversational, so I work written-first and asynchronously: precise specs, comments and demos rather than long calls. My Upwork record is small because I kept a full-time job through most of my career; I am rebuilding it deliberately, starting with scopes I can over-deliver on. Tell me what breaks today and I will tell you what I would change first — and what I would leave alone.