Multi-tenant platforms
Products that serve many customers off one codebase without leaking between them. Tenancy drawn at the data layer rather than patched in at the handler, self-serve onboarding, roles and permissions that survive the second and third customer asking for something bespoke.
Recent shape of work: a creator platform with per-tenant isolation and self-serve setup.
Payments and money movement
Checkout, subscriptions, payouts, refunds, reconciliation. Money paths get idempotency keys, an append-only record of what happened, and webhook handling that assumes duplicates and out-of-order delivery, because both happen. The ledger is the source of truth, not the UI.
Recent shape of work: payment and payout flows for a platform paying out to third parties.
AI agents and internal tooling
Automation that removes a real, named, repetitive job rather than demoing well. Tool-calling agents with tight boundaries, human review where a mistake is expensive, and evaluation you can run before a change ships instead of finding out in production.
Recent shape of work: agent tooling that replaced manual back-office processing.
Infrastructure and delivery
CI that actually gates, environments that match, migrations that run without a maintenance window, and logs and alerts good enough to diagnose an incident at 3am. Handing over a system nobody else can operate is not finishing.