Application architecture
Full-stack TypeScript systems with explicit boundaries across interface, API, domain logic, and persistence.
About / professional profile
Software engineering with explicit ownership.
I am Yerikho William Tasilima, a Software Engineer focused on full-stack TypeScript systems and PostgreSQL-backed business workflows.
My work emphasizes observable behavior: define the rule, make the trade-off visible, and verify the result at the boundary where it can fail.
Current focus
Where I go deepest.
Data integrity
Transaction flows examined through invariants, concurrency behavior, ledger consistency, and failure states.
Verification
Claims connected to reproducible tests, documented decisions, and public implementation evidence.
How I work
Follow the system from business rule to failure mode.
A feature is more than its interface. I trace the request through validation, domain rules, transactions, persistence, and user-visible recovery so correctness is owned across the full path.
Evidence before adjectives
Published results remain bounded by their test scenario. Repositories, architecture decisions, and test records are linked only when they are genuinely public.
Inspect the work, then start a conversation.
The project index shows the publishing contract; OhMyPos source provides the deeper public implementation evidence.