A robo-advisor that takes a new client from sign-up to a live, diversified portfolio in 15 minutes, then quietly rebalances $25M+ in assets while everyone sleeps.
Every portfolio carries a target allocation with per-asset drift bands. A nightly EventBridge job sweeps every account, and any holding outside its band is queued for correction.
The Python optimizer doesn't just buy and sell to target, it accounts for tax lots, harvests losses where available, and avoids wash sales. Orders are batched and netted before a single call hits the custodian, keeping turnover and costs low.
In fintech, the ledger is the product. Every trade flows through a double-entry model in PostgreSQL, and nothing is marked complete until settlement is reconciled against the custodian's record of truth.
Mismatches halt automation and surface to an operator queue. That guardrail is exactly what lets 90% of the flow run untouched, the system only asks for a human when the numbers disagree.
| Component | Technology | Why |
|---|---|---|
| Account aggregation | Plaid | Bank-grade OAuth and normalized holdings across 12k+ institutions |
| Portfolio ledger | PostgreSQL | ACID guarantees for money movement and audit trails |
| Optimizer & risk engine | Python | NumPy/SciPy for allocation math and tax-lot optimization |
| API & order routing | Node.js | Async I/O suited to high-volume custodian webhooks |
| Scheduling & infra | AWS (ECS, EventBridge, RDS) | Managed, encrypted, horizontally scalable rebalancing jobs |
| Onboarding flow |
Drift-triggered trades keep every portfolio aligned to its target model without manual review.
The optimizer captures realized losses and routes around wash-sale windows automatically.
Plaid Link verifies and imports external holdings in a single OAuth handshake.
Allocations are honored to the dollar, so small balances stay fully diversified.
Every cash and security movement is recorded with an immutable, auditable trail.
Post-trade fills are matched against custodian records before any state is finalized.
“"The system only wakes a human when the numbers disagree, the other 90% just runs."”
What started as a manual advisory workflow now runs as an automated pipeline managing $25M+ in client assets. Onboarding dropped from days of paperwork to a 15-minute self-serve flow, and 90% of the operational load, profiling, drift detection, trade generation, execution, and reconciliation, happens without a person in the loop. The result is a platform where engineers maintain guardrails instead of pushing trades, and clients get institutional-grade, tax-aware rebalancing at robo-advisor scale.
| React + Plaid Link |
| Drop-in UI that compresses KYC to minutes |