Context
Before founding a company I worked on two systems where the constraint was scale rather than novelty: a price-comparison portal with up to 18 million monthly active users, and a bank programme analysing customer behaviour in real time.
Business problem
At the portal, accounts existed in one market and the login did not work in the others, so acquisition stopped at the border. In the bank, marketing decisions were made on yesterday’s data while customers were acting now.
My mandate
At the portal I was a key contributor — not the lead — to the internationalisation of the single sign-on systems that made the six-country login rollout possible, alongside cross-team development, architecture work and on-call. In the bank programme I worked on one of its projects, customer behavioural analysis with machine learning and real-time processing, as the person responsible for data orchestration and the pipelines.
Decisions
- Ship changes to the login and account flows behind A/B tests, with the results analysed against acquisition metrics, so the rollout was steered by measurement.
- Build the high-performance paths on Kafka, NoSQL stores and WebSockets, with production-ready microservices and REST APIs in Java and Kotlin on Spring Boot, Spring Security and Hibernate.
- Carry on-call for what we built, and take part in the migration from on-premises infrastructure to AWS rather than treating infrastructure as somebody else’s concern.
- In the bank, stream processing on Kafka, Flink and Camel feeding SAS Event Stream Processing and the real-time decision manager, which became one of the first event-stream-processing implementations of its kind in the European Union.
- Write a lineage plugin for the data-integration tooling that presented ETL flows and data lineage for compliance purposes; data analysts across the international group adopted it.
Delivery
The login rollout reached six countries and produced 1.4 million new accounts in three months, 700% over the forecast, and the single sign-on internationalisation was followed by an increase of more than 300% in customer acquisition. The banking platform ran behavioural analysis on thousands of events per second and served personalised offers adapted to the signals it saw.
Outcome
Two production systems at a scale where design mistakes are expensive: one consumer-facing across six markets, one inside a bank under compliance obligations.
Reuse
The streaming patterns, the habit of A/B-testing identity changes and the lineage tooling all carried forward — the last of them literally, into the rest of the group.
Evidence
Account numbers, forecast comparison, acquisition increase and country count are the employer’s records; my part in the single sign-on internationalisation was as a key contributor, not as its lead. Event throughput and the scope of the banking work are project records. I worked on one project within that programme and was not part of its founding team.