Full-Stack Engineer
Bolão do UOL
World Cup prediction platform engineered for high-traffic live sports events.
Bolão do UOL is a World Cup prediction platform with match predictions, private groups, rankings and scoring history. The product was built with Angular, NestJS and PostgreSQL for a high-concurrency live sports context.
I used k6 load tests and Azure Application Insights to evaluate request throughput and observe service and database behavior under concurrent load.
Context
Challenge
Prepare a World Cup prediction experience for sharp concurrency peaks while keeping group, ranking and scoring workflows responsive.
Execution
Engineering improvements
- Built match prediction, private group, ranking and scoring-history experiences.
- Created k6 load scenarios to measure the platform under concurrent traffic.
- Used Azure Application Insights to inspect service and database behavior during the tests.
Trade-offs
Architecture decisions
- Used Angular for the interactive product experience and NestJS with PostgreSQL for the API and persistence layers.
- Kept observability evidence inside the case study so performance claims remain tied to test results.
- Reported test throughput and passing checks separately from production audience claims.
Measured and verified
Evidence
- ~418 requests/second
- 99.73% of load-test checks passed
- k6 + Application Insights
Delivered value
Outcome
k6 load testing reached approximately 418 requests per second, with 99.73% of checks passing.
- Development date
- 2022
- Tags
- Web, APIs
- Main technologies
- Angular, NestJS
- Links
- Bolão do UOL
Product views and engineering evidence
Project gallery
Main Bolão do UOL experience for the World Cup competition. Match prediction flow for submitting picks. Private group invitation flow for competing with friends. Azure Application Insights evidence captured during concurrent load testing. Database connection behavior observed during performance testing.
Interested in the way I approach product engineering?