Contextual bandits & real-time optimisation
Built some of the first real-time contextual bandit systems for high-volume recommendations in the Nordics, and real-time webpage optimisation for fashion retail. Constraints: per-observation online updates, partial (bandit) feedback, non-stationary reward distributions, and serving inside sub-second request budgets. Evaluation done off-policy (IPS / doubly-robust) rather than on live traffic where experimentation was constrained.
Technical advisory for M&A
Technical due diligence during a 50+ MEUR acquisition, on behalf of the purchaser. Audited the defensibility, security, scalability, and quality of a SaaS product, including interviewing engineers to understand key challenges and opportunities from the expert level.
Bidding under partial information
Bidding algorithms for second-price advertisement auctions under partial information, allocating ten-digit (€1B+) annual media budgets. Constraints: censored feedback from lost auctions, budget pacing, and non-stationary competition.
Causal estimation of bonus program retention
Estimated the causal impact on retention of a third-party bonus/loyalty program carrying eight-digit (€10M+) annual license fees, to decide whether the spend was actually driving incremental behaviour. Constraints: no clean randomised holdout, confounding from self-selecting engaged users, and a decision that had to withstand scrutiny. Used instrumental-variable regression and difference-in-differences to isolate the effect; the incremental retention did not justify the fees, and the program was decommissioned, saving €10M+ annually.
High-availability payments infrastructure
Implemented payment processing (charges, holds, automatic refunds) and high-availability hosting for retail with multi-million annual revenues, alongside event-driven backends and a storefront for personalised fashion.
Global commerce replatforming
Architected and shipped a composable, event-driven commerce platform for global fashion retail: headless CMS, commerce engine, payments, tax, and personalisation services, replacing a monolithic platform that couldn't absorb traffic spikes or multi-channel content reuse. Constraints: zero-downtime migration of a live revenue stream, multi-market catalogues, pricing and tax, and content authored once but published across web, email, SMS, and B2C channels.