Alex Rivera

Backend Engineer · distributed systems & payments

Backend engineer who turns flaky, hard-to-reason-about services into systems teams trust at 3am. I've spent eight years on payments and event pipelines where a dropped message costs real money. Happiest deep in a trace, shaving p99s and deleting code that shouldn't exist.

02

Selected work

Idempotent settlement pipeline

Rebuilt money movement on an append-only event log with deterministic replay, so a retried payout can never double-pay.

Zero duplicate payouts across 4M+ daily transactions; reconciliation time down 70%.

Checkout latency teardown

Profiled the full checkout path, collapsed N+1 ledger reads into a single batched projection, and added request-level tracing.

p99 latency 820ms → 190ms; checkout error rate down 4x.

03

Experience

2021-03 — NOW

Staff Backend Engineer

Lumen Payments

• Re-architected the settlement pipeline onto an idempotent event log, cutting duplicate payouts to zero across 4M+ daily transactions.
• Drove p99 checkout latency from 820ms to 190ms by replacing N+1 ledger reads with a batched projection.
• Mentored four engineers and ran the on-call rotation; halved page volume in two quarters.

2017-06 — 2021-02

Senior Software Engineer

Northwind Logistics

• Built the real-time tracking service (Elixir + Postgres) powering shipment ETAs for 2,000 carriers.
• Introduced contract testing across six services, eliminating a recurring class of integration outages.

04

Toolkit

ElixirGoPostgreSQLEvent-driven architectureKafkaDistributed systemsObservabilityKubernetes