David O.

I turn messy, high-stakes data into decisions people can act on. Over 15+ years and 66 Upwork contracts (~4.9/5 stars across rated jobs, 84% perfect 5.0s), I've built my practice on one promise: you get a clear answer, a tool your team can actually use, and plain-English communication throughout. What I do best: * Interactive R Shiny dashboards and analysis platforms: 12+ shipped, including a 20+ package bioinformatics platform and a no-code causal-inference tool for pharmaceutical analysts * Machine learning and predictive modeling: injury prediction for an NFL franchise, mortgage default risk, game simulation * Statistical analysis: hierarchical Bayesian modeling, MaxDiff and survey analytics, meta-analysis, causal inference * R package development: a production package built over a 952-hour flagship engagement, plus a released CRAN package * Quantitative finance: DCC/GARCH modeling, asset allocation, backtesting frameworks Domains I know well: healthcare and EHR data, bioinformatics and genomics, finance and trading, marketing analytics, survey research, and sports. How I work: independently, end to end. Most clients hand me a problem, not a spec. I scope it, deliver in agreed milestones, and explain the results so non-technical stakeholders can make the call. That approach is why most of my work is repeat business, and why "Committed to Quality" and "Clear Communicator" are my two most-endorsed client tags. M.S. in Bioinformatics from Johns Hopkins. Co-author on 8 peer-reviewed papers. US-based native English speaker. If you have data that should be driving a decision and isn't yet, let's talk.