Huiru Feng · Sofhrina

selected-work · built and rebuilt

What survived the process.

Not a wall of tools. A few problems, the work I contributed, and what changed after I looked again.

selected-projects.txt

The technical choices are kept inside their context. Where a result is uncertain, that uncertainty stays on the page.

Jun – Aug 2026
WXML · WXSS · JavaScript

Mishi: enterprise canteen pre-ordering

Mishi is a three-role WeChat mini-program for employees, stall operators and administrators across Inspur's internal canteens. During a seven-week internship, I owned the employee-facing module: restaurant and dish discovery, search, multi-stall cart management, pre-orders, pickup codes, order tracking, reviews, likes and favourites.

I rebuilt the ordering pipeline around consistent API fields, vendor-level grouping, preserved price precision, synchronised lifecycle states and duplicate-submission protection. I also added an authenticated Node.js and Express review endpoint with validation and ownership checks, and refactored the interface across 105 files into reusable design tokens and centralised theme configuration.

Quality350+ Jest tests across 16 suites covering services, permissions, state and core user flows.
IntegrationA 33-file cross-branch merge connected the employee and stall-operator workflows.
StatusMy module was feature-complete and merged to the development branch; the wider product ended before production launch.

Open the Mishi repository →

May – Jun 2026
Python · Jupyter · Matplotlib

Algorithms and Big-O

A first-year algorithms project combining implementation, experiment and proof. I wrote bubble sort, merge sort, quicksort and counting sort from scratch, then timed them on inputs from 100 to 10,000 elements and plotted their growth on a logarithmic scale.

The repository also preserves the presentation, speaker notes, visual assets and my reconstruction of the decision-tree lower bound for comparison sorting. The important lesson was learning to distinguish recognising a proof from being able to rebuild it.

BuiltFour sorting implementations and reproducible timing experiments.
ExplainedO(n²), O(n log n), O(n+k), and the Ω(n log n) lower bound.
EvidenceCode, slides, notes and final assets are public.

Open the Big-O repository →

Jan – Mar 2026
Project lead · UCL

Cross-sectional alpha strategy: auto-sector reversal model

I led the end-to-end development of a cross-sectional prediction pipeline across nine global automotive equities, contributing roughly 80% of the quantitative architecture and core code. The model uses ranked momentum, RSI and volatility features with strict temporal separation and a shallow Random Forest to look for reversal signals in noisy price series.

The 12-month out-of-sample test produced a daily Spearman Rank IC of 0.0386. I treat that as a research result, not a live-trading claim: turnover control, transaction costs and signal smoothing remain necessary extensions before the model could support an investable strategy.

UniverseNine global automotive equities.
ValidationStrict temporal separation and a 12-month out-of-sample period.
ResultDaily out-of-sample Rank IC of 0.0386.

GitHub repository →

Feb – Mar 2026
UCL · Cambridge · LSE · Imperial

Strategic M&A valuation

Our cross-university team acted for Samsung Electronics, selected Lattice Semiconductor as a potential acquisition target, and built the strategic and financial case for a multi-billion-pound transaction.

I led the modelling: cleaning historical financials, setting operating assumptions, building a five-year revenue, margin and cash-flow forecast, and linking CAPM-based WACC, DCF and comparable-company analysis. The model and pitchbook contributed to a Top 100 finish among more than 100 teams in the UK and Europe competition.

RoleLead on valuation and quantitative modelling.
MethodsFive-year forecast, DCF, trading comps, WACC and sensitivity analysis.
OutputA linked Excel valuation model and team pitchbook.

Apr 2026
seven-person cross-university team

AI wearable concept

A companion wearable concept for detecting patterns associated with anxiety in university students. I handled market sizing, competitor mapping, product gaps and the route to the intended users.

The project forced a distinction between what a sensor might measure, what a model might infer and what a product should be allowed to claim. That uncertainty became part of the proposal rather than something to hide.

My partMarket sizing, competitor analysis and go-to-market logic.
ConstraintAvoiding medical claims beyond the evidence.
OutcomeA scoped concept and cross-university team presentation.